What's the difference between sarcasm and irony?

Sarcasim is saying the oppisot irony is when somthing happens at agunny time

Sarcasm is when you are basically saying the opposite of the statement, and irony is when you're saying, like, no to something you JUST did, but the no to someone else. Too confusing???
Basically, the difference between sarcasm and irony is me. I do both. LOL.

http://dictionary.reference.com/browse/sarcasm?s=t

http://dictionary.reference.com/browse/irony?s=ts

Basically, sarcasm is usually ironic but irony isn't necessarily sarcastic...

well, sarcasm is when someone says the exact opposite of the actual answer, in a way that shows the answer is obvious. Irony is for example, i say "you cant have ice cream!" while eating a jar of ice cream. basically the same as hypocrite