what does friendship means?

in my mind, friends are those who accept who you are and won't hurt you but today, i hurt by some of the people i thought they were my friends... I don't know y suddenly i hate them so much and can't forget the sentences they posted in a forum... Mayb im too stupid coz really treat them as my friend and they didn't care bout my feeling at all... now, i knew the real face of human! the people who always be nice to you sometimes won't be your real friend! they are just pretending and will a find a chance to shot you!!