GLOSSARY OF DIGITAL TERMS
A compendium of frequently-used terms, abbreviations and standards used in the digital media world.
Alternate Reality Game (ARG). A style of computer game that involves everyday touch points to involve the user and affect the outcome of the game. The genre typically utilizes interactive puzzles and messaging on multiple media including email, cell phones and websites to immerse players into the story. ARG's have recently begun to appear as mainstream entertainment properties; the Fallen Alternate Reality game, produced in the fall of 2007 by Xenophile Media, won a Primetime Emmy for Outstanding Achievement for an Interactive Television Program.
API (Application Programming Interface) – Routines, protocols and tools programmers use to build software applications. For years, software and hardware companies carefully guarded their APIs to make sure they could control and approve what was developed for their platforms. More recently, open source practices are being adopted, making API’s available to the public to encourage independent developers to create new applications for particular platforms.
Aspect Ratio - The ratio of the width of a film frame to its height. The 4 to 3 "academy ratio" is used for standard def. TV and most video on the web. The HDTV format has an aspect ratio 16:9.
Avatar - graphic representation of a person online, usually used to navigate a virtual world such as Second Life. Some try to make their avatars look like themselves, and others go for idealized/stylized visions. Japanese anime characteristics – larger heads and eyes – are often the norm.
AVI (Audio Video Interleaved) - A Microsoft format for digital audio and video playback from Windows 3.1. Somewhat cross-platform, but mostly a Windows format. Has been replaced by the ASF format, but still used by some multimedia developers.
Bandwidth - A measure of the amount of data that can travel through a network. Once measured in kilobits per second (Kbps), megabits (1 million bits) per second are more relevant in the broadband era.
Bit Rate - The number of bits transmitted per second. Dial-up maxes out at 56 kilobits per second while broadband via DSL, cable modem, fiber optic cable or WiFi can transmit anywhere from 400k to 8 megabit per second and beyond.
Blog/Vlog - Online text or video diaries covering a range of topics, from personal reflections to highly specialized industry news. Many web companies maintain their own corporate blog where informal announcements are made to their communities of users. More popular blogs earn ad revenue, break news, attract buyout offers and have even been known to influence national debate or stock prices. Platforms such as Google-owned Blogger, TypePad and WordPress have turned blogging into one of the easiest ways for people to maintain a constantly updated web presence.
Buffering - A process used as a part of streaming media technologies whereby a certain amount of data is fed into the player to allow it to begin playing before fully downloading the file.
Byte - One of the basic units for measuring digital information, especially relevant to understanding storage capacity on computer disks. 8 bits comprise a byte. Roughly 1000 bytes equals one kilobyte. 1000 kilobytes is one megabyte or meg. 1000 megabytes is a gigabyte.
Client - The software that allows users the ability to retrieve information from the internet and World Wide Web. The Joost video player is an example of client software that resides on the desktop then connects to the web to retrieve video.
CODEC (Coder/Decoder) - A mathematical system for compressing (encoding) and decompressing (playing back) a video or audio file. CODECs can be hardware or software-based, or both. Hardware CODECS are often more efficient, but the trade-off is that not all users will have the special hardware needed to play back the file.
Compression - The process of reducing the size of a media file by eliminating data. Higher compression means that the compression utility defines greater amounts of data as redundant. This can lead to loss of image quality, but highly compressed images can be delivered more efficiently over a network.
Data Rate - An attribute assigned to a media file by a compression utility. It is a measure of the amount of digital information transmitted in a given unit of time—usually a second. Thus, a video could be encoded to play back at a rate of 500 kb/s.
Digitize - To convert analog (wave-based) media into digital format (zeros and ones) so that they can be understood by computers. Also known as "capturing," and sometimes "encoding."
DPI (Dots Per Inch) - A measure of image resolution.
DRM (Digital Rights Management) - A technology that allows content owners to determine and control who and how users can view content such as media files on the internet.
Embed Tag - An HTML tag used to place a media file (such as an audio, video, or Flash file) into a web page. The embed tag defines an area on the page in which the media file will appear if it involves graphic elements, helps the browser understand what type of file it is, and specifies other info such as whether the file will play automatically when the page loads. Embedded media are contrasted to media controlled through a separate player, such as when the Windows Media player pops up over your web browser to display a video.
Encoding - The process of compressing a media file for a specific purpose, such as streaming on the Web.
Flash – The authoring tool and format developed by Macromedia (acquired by Adobe Systems in 2005) to create content for digital platforms such as web applications, games, movies. It has become the preferred standard for adding animation and interactivity to web pages and is commonly used to integrate video and develop rich media applications.
Frames Per Second (fps) - The number of video frames displayed each second (also called frame rate). Continuous motion is believed to be achieved at about 17 fps. A common standard for video delivered over the web is 15 fps, which reduces file sizes substantially (since most video is shot at roughly 30 fps) but still but allows for fairly smooth motion.
Fullscreen - A way of viewing images in which the content is accommodated to the size of the monitor you are using. This can result in noticeable distortion if the data rate of file is too low.
Full Motion - Refers to NTSC-quality video—a video signal that is 30 fps, and at least 640x480 pixels in size.
Gigabyte (GB) - A unit of measure equal to 1,000 megabytes.
HDTV – High Definition Television, a format with significantly higher resolution than standard NTSC, SECAM or PAL, broadcast either in 720p or 1080i, referring to the lines of vertical resolution. HDTV also has a screen ratio of 16:9 as compared with traditional TV screens, which have a screen ratio of 4:3. HDTV offers reduced motion artifacts (i.e. ghosting, dot crawl), and offers 5.1 independent channels of CD-quality stereo surround sound, (also referred to as AC-3).
Hotspotting - The practice of embedding hyperlinks within online video to enable users to click on actors, characters’ articles of clothing or other objects within the frame for more information or the opportunity to purchase.
HTML (HyperText Markup Language) - The rules that govern the way documents are created so they can be read by a world-wide-web browser.
HTTP (HyperText Transport Protocol) - The protocol through which web pages are transmitted over the Internet.
Hyperlink - A web link in a given document to information within another document. These links are usually represented by highlighted words or images. The user also has the option to underline these hyperlinks.
HTTP Streaming - A form of streaming (popularized by QuickTime) in which media files begin to play before they are downloaded entirely. This means that they can be sent via HTTP and don't require specialized server software such as RealMedia files do. Also called Progressive Download.
IP (Internet Protocol) - The basic language of the internet. It was developed by the government for use in connecting multiple computer networks.
ISP (Internet Service Provider) - A company that allows users to connect to the internet, usually through a dial up, cable, DSL or fiber-to-the-home modem. Wireless ISPs such as ClearWire are also emerging.
Java - An object-oriented programming language that is platform independent (i.e., works on Windows, Mac OS, Linux). Java is often used to write "java applets," which are small applications that can be embedded into web pages, giving the pages sophisticated functionality.
JPEG (Joint Photographic Experts Group) - Refers to an image file format popular for delivery over the Web because of its relatively high quality and low file size. Before uploading JPEGs to the Web, users can determine the amount of compression assigned to them-usually on a scale from 1 to 10.
Machinima – a user generated genre of digital film production created from the same 3D computer-generated imagery (CGI) used in interactive gaming and virtual world content. Machinima (short for Machine Cinema) films often utilize the same characters featured in games such as Quake, Half Life and The Sims.
Malware – Software designed to infiltrate a user’s computer system without his or her consent. The nasty pieces of code take the form of viruses, worms, Trojan horses, spyware or adware designed to erroneously inflate click-through or usage numbers.
Mashup - A web service or software tool that combines two or more tools to create a whole new service. A famous example is ChicagoCrime, which merges Google Maps with the Chicago police department's crime tracking web site to offer a map of crime in different parts of Chicago. The term is also used to describe user generated remixes of content from different sources.
Megabyte (MB) - A unit of measure equal to 1,000 kilobytes.
MPEG (Moving Picture Experts Group) - A series of International Organization for Standardization (ISO) standards for digital video and audio, designed for different uses and data rates.
* MPEG-1 was designed for playback of video on CD and includes MP3 for audio playback.
* MPEG-2 is the standard for DVD video.
* MPEG-4 is the next-generation format improving adaptability and flexibility for use in digital television, animation graphics, web video and its extensions, offering more control and copyright protection functionality.
Multicast - Method of carrying a compressed video signal across multiple routers to various clients in streaming media.
Newsreader - Gathers the news from multiple blogs or news sites via RSS (see below), allowing readers to access news from a single web site or program. Online newsreaders (like Bloglines, Pluck, or Newsgator) are web sites that allow you to read RSS feeds from within your web browser. Desktop newsreaders download the news to your computer, and let you read your news inside a dedicated software program.
NTSC - The video input signal formats used in North America and Japan. Full-sized NTSC has 525 total lines of resolution (480 visible) per frame.
Open Source - A movement in which software developers make their source code available to anyone for free collaboration. The Linux operating system, created by Linus Torvalds, was an early example, relying on an army of volunteers to keep it up to date.
PAL (Phase Alternating Line) - The European standard for television transmission representing 625 lines of resolution (576 lines viewable).
Peer-to-peer (P2P) – Relies primarily on the computing power and bandwidth of the participants in the network rather than concentrating it in a relatively low number of servers. Although Napster no longer allows the free sharing of music from one user to another, it helped spawn video companies such as BitTorrent that utilize P2P protocol to distribute video.
Phishing - Using social engineering techniques to fraudulently obtain a user’s sensitive personal information–such as usernames, passwords, credit card numbers and bank account details–for nefarious purposes. It’s typically done by sending bogus emails or IM’s that direct users to a website that requests additional information.
Podcasting - The iPod created a boom in internet audio, allowing users easily record their own radio-style shows and put them online for others to download or subscribe to. Video podcasts add moving images to the mix.
QuickTime - A digital audio and video file-format and architecture developed by Apple. Can be viewed on most computing platforms.
RSS (Really Simple Syndication) - Format for storing online information to make it readable by many different kinds of software. Many blogs and web sites feature RSS feeds, constantly updated in a form that can be read by a newsreader or aggregator.
SECAM - The video format used in France and some other countries. SECAM has 625 lines total (576 lines visible) per frame, and has a frame-rate of 25 frames per second.
Server - A computer that “serves” centralized information, either to a local group or the Internet.
Social Networking - Web sites that allow people to link to others to share opinions, insights experiences and perspectives, whether it’s music fans on MySpace, business contacts on LinkedIn, or classmates on Facebook. Many media sites have adopted social networking features such as blogs, message boards, podcasts and wikis to help build online communities around their content.
Streaming Media - Video or audio transmitted over a network that users can begin to play immediately instead of waiting for the entire file to download. Typically a few seconds of data is sent ahead and buffered in case of network transmission delays. (Although some data is buffered to the hard drive, it is written to temporary storage and is gone once viewing is complete.) RealMedia, QuickTime and Windows Media are the most common streaming formats.
Tags - Keywords attached to photos or Web pages to help identify them and allow them show up in search engines. Photos on Flickr typically carry many tags. The social bookmarking manager Del.icio.us allows users to post their favorite Web sites and then tag them, creating a new tool for searching those sites.
URL (Uniform Resource Locator) - The address to a source of information on the web. The URL contains four distinct parts, the protocol type, the machine name, the directory path and the file name.
Wireless Application Protocol (WAP) - is the open international standard for applications written for cell phones or other wireless devices including Blackberrys and PDAs. A WAP browser surfs sites written to the standard, just like an internet web browser does.
Webcasting - Communicating to multiple computers at the same time over internet by "streaming" live audio and/or live video through compression and decompression of the signal.
White Label Product or Service – A product or service created by one company and sold to another to be rebranded as their own. In the digital world, white labels can apply to web applications, widgets or even entire networks. For instance Ning is a white label social networking service started by Netscape founder Marc Anderssen that companies can use to create their own social network.
Widget - A small downloadable application that resides on a computer's desktop or can be embedded on blogs, social networking profiles, personal start pages or other websites. Widgets can play audio or video tracks, conduct polls or quizzes, run slideshows or provide news o stock prices, or a multitude of other minor tasks.
Wiki - A collaboratively edited web page. The best-known example is wikipedia, an encyclopedia that anyone in the world can help to write or update. Wikis are frequently used to allow people to write a document together, or to share reference material that lets colleagues or even members of the public contribute content.
Windows Media - A media format developed by Microsoft for streaming and playing back media files.
XML (Extensible Markup Language) – A general purpose standard for describing, or marking up, documents and data distributed on the web. XML allows authors to create customized tags that can help them efficiently achieve their goals.