A retweet puts the tweet into your public feed, as if you had tweeted it (of course, in the UI it is correctly attributed to the original author). A favorite/st

A retweet puts the tweet into your public feed, as if you had tweeted it (of course, in the UI it is correctly attributed to the original author). A favorite/star/heart/like/"the other button", just flags the tweet in your account so that you can refer to it easier later (in another, less public feed).