• Well suppose a basic tweet is akin to a basic status update. Except you're restricted to 140 characters and have no control over who sees your message. Your Facebook pals can see your status updates. Those who follow you on Twitter (even if you don't follow them back) see your tweets in their timelines.
• People can also remark directly within a Facebook Status Update, whereas Twitter is essentially a series of back-and-forth messages.
• There are some parallels, but they are fundamentally different. 
• On Facebook, people do not 'share' a friend's status update. Your tweet, on the other hand, can soon be retweeted by thousands of people. As a result, bear that in mind. Don't tweet anything you'll regret because your message could reach a big audience rapidly.

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