Encription
In cryptography, encryption is the process of transforming information (referred to as plaintext) using an algorithm (called cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information (in cryptography, referred to as ciphertext). In many contexts, the word encryption also implicitly refers to the reverse process, decryption (e.g. “software for encryption” can typically also perform decryption), to make the encrypted information readable again (i.e. to make it unencrypted).Electronic mail, commonly called email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the same time, a la instant messaging. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver and store messages. Neither the users nor their computers are required to be online simultaneously; they need connect only briefly, typically to an email server, for as long as it takes to send or receive messages.
Home Page
A home page or homepage has various related meanings to do with web sites:
- It most often refers to the initial or main web page of a web site, sometimes called the front page (by analogy with newspapers).
- The web page or local file that automatically loads when a web browser starts or when the browser's "home" button is pressed; this is also called a start page. The user can specify the URL of the page to be loaded, or alternatively choose e.g. to re-load the most recent web page browsed.
- In the 1990s the term was also used to refer to a whole web site, particularly a personal web page (perhaps because simple web sites often consisted of just one web page).
Electronic commerce, commonly known as e-commerce, eCommerce or e-comm, consists of the buying and selling of products or services over electronic systems such as the Internet and other computer networks. It is more than just buying and selling products online. It also includes the entire online process of developing, marketing, selling, delivering, servicing and paying for products and services. The amount of trade conducted electronically has grown extraordinarily with widespread Internet usage. The use of commerce is conducted in this way, spurring and drawing on innovations in electronic funds transfer, supply chain management, Internet marketing, online transaction processing, electronic data interchange (EDI), inventory management systems, and automated data collection systems. Modern electronic commerce typically uses the World Wide Web at least at some point in the transaction's lifecycle, although it can encompass a wider range of technologies such as e-mail, mobile devices and telephones as well.
Editable Text
Edit the text (enable changing the text already entered)
A typical text box is a rectangle of any size, possibly with a border that separates the text box from the rest of the interface. Text boxes may contain zero, one, or two scrollbars. Some text boxes may display a blinking vertical line (known as a caret), indicating the current region of text being edited. It is common for the mouse cursor to change its shape when it hovers over a text box.
Error 404
The 404 or Not Found error message is a HTTP standard response code indicating that the client was able to communicate with the server, but the server could not find what was requested. 404 errors should not be confused with "server not found" or similar errors, in which a connection to the destination server could not be made at all. A 404 error indicates that the requested resource may be available again in the future.
Facebook is a social networking service and website launched in February 2004, operated and privately owned by Facebook, Inc.[1] As of January 2011, Facebook has more than 600 million active users.[5][6] Users may create a personal profile, add other users as friends, and exchange messages, including automatic notifications when they update their profile. Facebook users must register before using the site. Additionally, users may join common-interest user groups, organized by workplace, school or college, or other characteristics. The name of the service stems from the colloquial name for the book given to students at the start of the academic year by university administrations in the United States to help students get to know each other better. Facebook allows any users who declare themselves to be at least 13 years old to become registered users of the website.
Facebook was founded by Mark Zuckerberg with his college roommates and fellow computer science students Eduardo Saverin, Dustin Moskovitz and Chris Hughes.
Fixed Wireless
Fixed wireless is the operation of wireless devices or systems used to connect two fixed locations (e.g., buildings) with a radio or other wireless link, such as laser bridge.[1] Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications between the two sites or buildings. Fixed wireless data (FWD) links are often a cost-effective alternative to leasing fiber or installing cables between the buildings.
The point-to-point signal transmissions occur through the air over a terrestrial microwave platform rather than through copper or optical fiber; therefore, fixed wireless does not require satellite feeds or local telephone service. The advantages of fixed wireless include the ability to connect with users in remote areas without the need for laying new cables and the capacity for broad bandwidth that is not impeded by fiber or cable capacities. Fixed wireless devices usually derives their electrical power from the public utility mains, unlike mobile wireless or portable wireless devices which tend to be battery powered.
Forms
A form is a document with spaces (fields) in which to write or select, for a series of documents with similar contents. The documents usually have the printed parts in common, possibly except for a serial number. Advantages of forms include:
- one has to write less (while the printing is almost universally done in some automatic way)
- one is told or reminded what information has to be supplied
- uniformity, for convenience in processing
Forms, when completed, may be a statement, a request, an order, etc., e.g. a check may be a form. Also there are forms for taxes; filling one in is a duty to have determined how much tax one owes, and/or the form is a request for a refund. See also Tax return.
Forms may be filled out in duplicate (or triplicate, meaning three times) when the information gathered on the form needs to be distributed to several departments within an organisation. This can be done using carbon paper.
Forms have existed for a significant amount of time, with historians of law have discovered preprinted legal forms from the early 19th century that greatly simplified the task of drafting complaints and various other legal pleadings. It is believed that the form was conceived by mathematician and inventor Charles Babbage.[1] In some jurisdictions, like California, many common types of legal pleadings must be submitted on official government forms.
Blank forms are generally not copyrightable.[2]
File Size
File size measures the size of a computer file. Typically it is measured in bytes with a prefix. The actual amount of disk space consumed by the file depends on the file system.
The maximum file size a file system supports depends on the number of bits reserved to store size information and the total size of the file system. For example, with FAT32, the size of one file cannot be equal or larger than 4 GiB.
Some common file size units are:
- 1 KiB = 1,024 bytes
Feather
Feathering is a technique used in computer graphics software to smooth or blur the edges of a feature. The term is inherited from a technique of fine retouching using fine feathers.Feathering is most commonly used on a paintbrush tool in computer graphics software. This form of feathering makes the painted area appear smooth. It may give the effect of an airbrush or spraypaint. Color is concentrated at the center of the brush area, and it blends out toward the edges.
File extention
A filename extension is a suffix to the name of a computer file applied to indicate the encoding convention (file format) of its contents.
In some operating systems (for example Unix) it is optional, while in some others (such as DOS) it is a requirement. Some operating systems limit the length of the extension (such as DOS and OS/2, to three characters) while others (such as Unix) do not. Some operating systems (for example RISC OS) do not use filename extensions. Unix accepts the separator dot as a legal character but does not give it a special recognition on the OS level.
Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products,[4] and generates profit primarily from advertising through its AdWords program.[5][6] The company was founded by Larry Page and Sergey Brin, often dubbed the "Google Guys",[7][8][9] while the two were attending Stanford University as PhD candidates. It was first incorporated as a privately held company on September 4, 1998, and its initial public offering followed on August 19, 2004. At that time Larry Page, Sergey Brin, and Eric Schmidt agreed to work together at Google for twenty years, until the year 2024.[10] The company's mission statement from the outset was "to organize the world's information and make it universally accessible and useful",[11] and the company's unofficial slogan – coined by Google engineer Paul Buchheit – is "Don't be evil".[12][13] In 2006, the company moved to its current headquarters in Mountain View, California.
GIF File
The Graphics Interchange Format (GIF) is a bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability.
The format supports up to 8 bits per pixel thus allowing a single image to reference a palette of up to 256 distinct colors. The colors are chosen from the 24-bit RGB color space. It also supports animations and allows a separate palette of 256 colors for each frame. The color limitation makes the GIF format unsuitable for reproducing color photographs and other images with continuous color, but it is well-suited for simpler images such as graphics or logos with solid areas of color.
GIF images are compressed using the Lempel-Ziv-Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. This compression technique was patented in 1985. Controversy over the licensing agreement between the patent holder, Unisys, and CompuServe in 1994 spurred the development of the Portable Network Graphics (PNG) standard; since then all the relevant patents have expired.
Gaussian Blur
A Gaussian blur (also known as Gaussian smoothing) is the result of blurring an image by a Gaussian function. It is a widely used effect in graphics software, typically to reduce image noise and reduce detail. The visual effect of this blurring technique is a smooth blur resembling that of viewing the image through a translucent screen, distinctly different from the bokeh effect produced by an out-of-focus lens or the shadow of an object under usual illumination. Gaussian smoothing is also used as a pre-processing stage in computer vision algorithms in order to enhance image structures at different scales—see scale-space representation and scale-space implementation.
Grayscale
In photography and computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample, that is, it carries only intensity information. Images of this sort, also known as black-and-white, are composed exclusively of shades of gray, varying from black at the weakest intensity to white at the strongest.[1]
Grayscale images are distinct from one-bit bi-tonal black-and-white images, which in the context of computer imaging are images with only the two colors, black, and white (also called bilevel or binary images). Grayscale images have many shades of gray in between. Grayscale images are also called monochromatic, denoting the absence of any chromatic variation (ie: one color).
Grayscale images are often the result of measuring the intensity of light at each pixel in a single band of the electromagnetic spectrum (e.g. infrared, visible light, ultraviolet, etc.), and in such cases they are monochromatic proper when only a given frequency is captured. But also they can be synthesized from a full color image; see the section about converting to grayscale.
Gigabyte
he gigabyte (
/ˈɡɪɡəbaɪt/ gig-ə-byt) is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units (SI), therefore 1 gigabyte is 1000000000bytes. The unit symbol for the gigabyte is GB or Gbyte, but not Gb (lower case b) which is typically used for the gigabit. Historically, the term has also been used in some fields of computer science and information technology to denote the gibibyte, or 1073741824 (10243 or 230) bytes. The Institute of Electrical and Electronics Engineers (IEEE) defined the unit accordingly for the use in power switchgear.[1] In 2000, however, IEEE adopted the International Electrotechnical Commission (IEC) recommendation, which uses the metric prefix interpretation.
HTML
HTML, which stands for HyperText Markup Language, is the predominant markup language for web pages. HTML is the basic building-blocks of webpages.
HTML is written in the form of HTML elements consisting of tags, enclosed in angle brackets (like <html>), within the web page content. HTML tags normally come in pairs like <h1> and </h1>. The first tag in a pair is the start tag, the second tag is the end tag (they are also called opening tags and closing tags). In between these tags web designers can add text, tables, images, etc.
The purpose of a web browser is to read HTML documents and compose them into visual or audible web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page.
HTML elements form the building blocks of all websites. HTML allows images and objects to be embedded and can be used to create interactive forms. It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items. It can embed scripts in languages such as JavaScript which affect the behavior of HTML webpages.
Hyperlink
In computing, a hyperlink (or link) is a reference to a document that the reader can directly follow, or that is followed automatically.[citation needed] A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks. A software system for viewing and creating hypertext is a hypertext system, and to create a hyperlink is to hyperlink (or simply to link). A user following hyperlinks is said to navigate or browse the hypertext.
A hyperlink has an anchor, which is the location within a document from which the hyperlink can be followed; the document containing a hyperlink is known as its source document. The target of a hyperlink is the document, or location within a document, to which the hyperlink leads. Users can activate and follow the link when its anchor is shown, usually by touching or clicking on the anchor with a pointing device. Following the link has the effect of displaying its target, often with its context.
Helper Applicationns
A helper application is an external viewer program launched to display content retrieved using a web browser. Some common examples include Windows Media Player and QuickTime Player for playing streaming content.
Unlike a plugin(whose full code is included into browser code), a small line is added to the browser code to tell it to open a certain helper application in case it encounters a certain file format.
H.264 video
H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video. The final drafting work on the first version of the standard was completed in May 2003.
H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG). It was the product of a partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard (formally, ISO/IEC 14496-10 - MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content.
H.264 is perhaps best known as being one of the codec standards for Blu-ray Discs; all Blu-ray players must be able to decode H.264. It is also widely used by streaming internet sources, such as videos from Vimeo, YouTube, and the iTunes Store, web software such as the Adobe Flash Player and Microsoft Silverlight, broadcast services for DVB and SBTVD, direct-broadcast satellite television services, cable television services, and real-time videoconferencing.
Hard Drive
A hard disk drive[2] (HDD) is a non-volatile, random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters.
Introduced by IBM in 1956, hard disk drives have fallen in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s.[3] They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage.[3] Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI (SAS).
Hue
Hue is one of the main properties of a color, defined technically (in the CIECAM02 model), as "the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow,"[1] (the unique hues). The other main correlatives of color appearance are colorfulness, chroma, saturation, lightness, and brightness.
Usually, colors with the same hue are distinguished with adjectives referring to their lightness and/or chroma, such as with "light blue", "pastel blue", "vivid blue". Exceptions include brown, which is a dark orange,[2] and pink, a light red with reduced chroma.
Hostname
A hostname is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication such as the World Wide Web, e-mail or Usenet. Hostnames may be simple names consisting of a single word or phrase, or they may have appended the name of a Domain Name System (DNS) domain, separated from the host specific label by a full stop (dot). In the latter form, a hostname is also called a domain name. If the domain name is completely specified including a top-level domain of the Internet, the hostname is said to be a fully qualified domain name (FQDN).
Image Capture
Image Capture is an application program that enables users to upload pictures from digital cameras or scanners which are either connected directly to the computer or the network. It provides no organizational tools like iPhoto but is useful for collating pictures from a variety of sources with no need for drivers. It achieves this by "receiving the picture" as it is and through a conversion process, downloading it onto your computer. It uses QuickTime Image Capture.[1] This way it doesn't need to understand anything about the actual camera to be able to do that. It was first introduced in Mac OS X version 10.0 (Cheetah)
i Tunes
iTunes is a proprietary digital media player application, used for playing and organizing digital music and video files. The application is also an interface to manage the contents on Apple's iPod, iPhone and iPad.
iTunes can connect to the iTunes Store to purchase and download music, music videos, television shows, iPod Games, Audiobooks, Podcasts, movies and movie rentals (not available in all countries), and Ringtones (only available on iPhone and iPod Touch 4th Generation). It is also used to download Apps from the App Store for the iPhone, iPod Touch and iPad. iTunes has also been highly criticized for its lack of transferability of music from one portable device to another, and many predict that this feature will eventually lead other MP3 technology to displace iTunes as the dominant music platform.
iTunes was introduced by Apple Inc. on January 9, 2001.[1] The latest version, which is currently version 10.2.2, is available as a free download for Mac OS X v10.5/Windows XP or later on Apple's website. In June 2010, Apple released a new privacy policy pertaining to the capture and collection of users' real-time location information.[2] The information had been included in various device-specific EULAs since 2008, but was only recently included in Apple's general privacy policy.[3
Index Page
When an HTTP client (generally a Web browser) requests a URL that points to a directory structure instead of an actual Web page within the directory, the Web server will generally serve a general page, which is often referred to as a main or "index" page.
index.html is the traditional filename for such a page, but most modern HTTP servers offer a configurable list of filenames that the server can use as an index. If a server is configured to support server-side scripting, the list will usually include entries allowing dynamic content to be used as the index page (e.g. index.php, index.shtml, default.asp) even though it may be more appropriate to still specify the html output (index.html.php or index.html.aspx), as this should not be taken for granted. An example is the popular open source web server Apache, where the list of filenames is controlled by the DirectoryIndex directive in the main server configuration file or in the configuration file for that directory. It is possible to make do without file extensions at all, and be neutral to content delivery methods, and set the server to automatically pick the best file through content negotiation.
If the server is unable to find a file with any of the names listed in its configuration, it may either return an error (generally 404 Not Found) or generate its own index page listing the files in the directory. It may also return a 403 Index Listing Forbidden. Usually this option is also configurable.
Since the index page is often the first page of a Web site that a user sees, it is sometimes used to offer a menu of language options for large Web sites that use geo targeting. It is also possible to avoid this step, for example by using content negotiation.
ISDN (Intergrated Services Digital Network)
Integrated Services Digital Network (ISDN) is a set of communications standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. It was first defined in 1988 in the CCITT red book.[1] Prior to ISDN, the phone system was viewed as a way to transport voice, with some special services available for data. The key feature of ISDN is that it integrates speech and data on the same lines, adding features that were not available in the classic telephone system. There are several kinds of access interfaces to ISDN defined as Basic Rate Interface (BRI), Primary Rate Interface (PRI) and Broadband ISDN (B-ISDN).
ISDN is a circuit-switched telephone network system, which also provides access to packet switched networks, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in potentially better voice quality than an analog phone can provide. It offers circuit-switched connections (for either voice or data), and packet-switched connections (for data), in increments of 64 kilobit/s. A major market application for ISDN in some countries is Internet access, where ISDN typically provides a maximum of 128 kbit/s in both upstream and downstream directions. Channel bonding can achieve a greater data rate; typically the ISDN B-channels of 3 or 4 BRIs (6 to 8 64 kbit/s channels) are bonded.
ISP (Internet Service Provider)
An Internet service provider (ISP) is a company that provides access to the Internet. Access ISPs connect customers to the Internet using copper, wireless or fiber connections.[1] Hosting ISPs lease server space for smaller businesses and host other people servers (colocation). Transit ISPs provide large tubes for connecting hosting ISPs to access ISPs.[2]
IP Address
An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.[1] An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."[2]
The designers of the Internet Protocol defined an IP address as a 32-bit number[1] and this system, known as Internet Protocol Version 4 (IPv4), is still in use today. However, due to the enormous growth of the Internet and the predicted depletion of available addresses, a new addressing system (IPv6), using 128 bits for the address, was developed in 1995,[3] standardized as RFC 2460 in 1998,[4] and is being deployed worldwide since the mid-2000s.
IP addresses are binary numbers, but they are usually stored in text files and displayed in human-readable notations, such as 172.16.254.1 (for IPv4), and 2001:db8:0:1234:0:567:8:1 (for IPv6).
Javascript
JavaScript, also known as ECMAScript,[6] is a prototype-based, object-oriented[7] scripting language that is dynamic, weakly typed and has first-class functions. It is also considered a functional programming language[1] like Scheme and OCaml because it has closures and supports higher-order functions.[8]
JavaScript is an implementation of the ECMAScript language standard and is primarily used in the form of client-side JavaScript, implemented as part of a web browser in order to provide enhanced user interfaces and dynamic websites. This enables programmatic access to computational objects within a host environment.
JavaScript's use in applications outside web pages—for example in PDF documents, site-specific browsers and desktop widgets—is also significant. Newer and faster JavaScript VMs and frameworks built upon them (notably Node.js) have also increased the popularity of JavaScript for server-side web apps.
JavaScript uses syntax influenced by that of C. JavaScript copies many names and naming conventions from Java, but the two languages are otherwise unrelated and have very different semantics. The key design principles within JavaScript are taken from the Self and Scheme programming languages.[9]
JPEG File
The JPEG File Interchange Format (JFIF) is an image file format standard. It is a format for exchanging JPEG encoded files compliant with the JPEG Interchange Format (JIF) standard. It solves some of JIF's limitations in regard to simple JPEG encoded file interchange. As with all JIF compliant files, image data in JFIF files is compressed using the techniques in the JPEG standard, hence JFIF is sometimes referred to as "JPEG/JFIF".
