Email
E.g. Yahoo Mail, Hotmail, Google(Gmail)
Contact people quickly, no cost, archive
Versatile - pictures/attachments, send to groups

Forum
E.g. Wiki/Yahoo Answers, The Student Room
Online discussion site - hold conversations in order to ask questions and find answers.

Profile - Online biography that shows information written by an individual about themselves.
Network of friends - group of friends online that are linked together in some way e.g. Facebook.
Chat - Communication online in real time in a private chatroom usually between 2 or 3 people.
Netiquette - Online etiquette, the way you should behave online e.g. being aware of people's feelings.