There are2 eids one after ramadan ( sort of like easter at the end of lent. And one now which is the tenth day of dul hijah the month when people go off on haj/pilgramige. Basically one of the things to do with it is tHat abraham was willing to sacrifice his son for God but then at the last minute God said he could sacrifice a sheep instead and so we all sacrifice sheep ( or cows/goats/camels depending on how rich you are). Its alot more complicated than that but That is the simplified version.

