User-generated content (UGC)- refers to various kinds of media content, publicly available, that are produced by end-users.

Long Tail- a retailing concept describing the niche strategy of selling a large number of unique items in relatively small quantities – usually in addition to selling fewer popular items in large quantities.

Web operating system- terms that describe network services for internet scale distributed computing, as in the WebOS Project at UC Berkeley, and the WOS Project

Folksonomy- a system of classification derived from the practice and method of collaboratively creating and managing tags to annotate and categorize content; this practice is also known as collaborative tagging, social classification, social indexing, and social tagging.

Web syndication- a form of syndication in which website material is made available to multiple other sites.

Mass collaboration- a form of collective action that occurs when large numbers of people work independently on a single project, often modular in its nature.

Computer-supported collaboration (CSC)- research that focuses on technology that affects groups, organizations, communities and societies, e.g., voice mail and text chat.

web hosting service- a type of Internet hosting service that allows individuals and organizations to make their own website accessible via the World Wide Web.

web application- an application that is accessed via a web browser over a network such as the Internet or an intranet.

Social software- encompasses a range of software systems that allow users to interact and share data

video sharing site- web site that lets people upload and share their video clips to the public at large or to invited guests.

Wiki- a website that allows the easy creation and editing of any number of interlinked web pages via a web browser using a simplified markup language or a WYSIWYG text editor.

Blog- a type of website, usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video

Mashup- a web page or application that combines data or functionality from two or more external sources to create a new service.