From Wikipedia – ‘the trend in the use of World Wide Web technology and web design that aims to enhance creativity, information sharing, and, most notably, collaboration among users.Web 2.0 is about enriching the user-generated content on the web.

Glossary of Communication Services

1. Blog – a website , maintained by user, with regular entries of commentary, description of events, other material such as graphics or video. Entries are commonly displayed in reverse chronological order. Many blogs provide commentary or news on a particular subject; others function as more personal online diaries. A typical blog combines text, images, and links to other blogs, web pages, and other media related to its topic.


2. Forum – Internet Forum is a web-application to for holding discussions and posting user-generated content. Internet forums are also commonly referred to as Web forums, message boards, discussion boards, (electronic) discussion groups, discussion forums, bulletin boards, fora (the Latin plural) or simply forums.
   Interesting Note : The Forum was the public space in the middle of a Roman city. Modelled on the Roman Forum and Imperial fora in Rome itself, they are to be found in Italy (often forming the piazza of the modern town) and throughout the former Roman empire.


3. Poll - a method for a group such as a meeting or an electorate to make a decision or express an opinion — often following discussions, debates or election campaigns. An opinion poll is a survey of public opinion from a particular sample.
   4. Chat - Online chat can refer to any kind of communication over the Internet, but is primarily meant to refer to direct one-on-one chat or text-based group chat (formally also known as synchronous conferencing), using tools such as instant messaging applications.
   Note : word chat means "informal conversation".

Note : Above references are obtained from Wikipedia.