vampires

what are vampires? are they people who have a disease or are they realty immortal bloodsucking freaks well i would like to know i was resurching and i fund this site and it was like so cool but when i got to reading the information it was about how president obama was runing the world. and the title said it was about vamps it was not the right information to go with the name i mean comeon people get the facts right. i read a bunch of book on  the subject they were all diferent! what do you think that a vamp should be? because i can not figur it out what are they realy? if you have ideas then tell me about them if not just take a gess