Twitter –a website offering a social networking and microblogging service, enabling its users to send and read short messages called tweets.
An estimated 200 million users generate 65 million tweets a day.
Facebook –a social networking website with more than 600 million active users.
Wall – a space on every Facebook user’s profile page that allows friends to post messages for the user to see.
Followers –a person or entity who has a Twitter account who has gained access or the ability to follow or read another Twitter account holder’s tweets.
Friend –A Facebook user you have added either by requesting their permission, or responding to their request. By adding or agreeing to be friends you allow the person to view your profile and comment on your wall.