Twitter is a type of social network in which users submit "little messages" (140 characters or less), called tweets, in which users write all kinds of things, such as news, videos, photos or simply "rubbish". These messages are public and any user could read it, but you can also privatize the acCount and your tweets will not be public, that is, only the users you want will be able to read your tweets. To read other user´s tweets, you click on "follow" and you becOme his follower, so you can read all his tweets without having to go into his profile. In my opinion, Twitter is a very useful information tool if used effeciently, but most users don't use it THAT WAY.