The Guide to Laughing Online (my "how-to" dictionary)
When some people laugh online, they don’t actually know what they’re saying. Silly them… let me clarify the terminology. :)
haha = A casual laugh.
ha ha = A “Nelson” style laugh from the Simpsons, usually at someone else’s expense. Hear sample.
hah = Something you don’t really think is that funny, but you’re laughing more-or-less to be polite and to merit the honor of the other person trying so hard to be funny.
heh = This goes by the same terms as ‘hah’, but what you’re laughing at usually wasn’t supposed to be funny. For example: “I’m such an idiot.” — “heh.”
hehe = Generally, the other person has said something cute or crafty that’s made you feel silly. :)
lol = Giving this response means you just heard something that was actually ‘laughable’-funny, and you actually laughed on the other end… rather than just smiled and/or made a witty come-back. Congratulations to the person you’re chatting with.
LOL or lolol = Think of this as lol, squared. Chances are you will remember laughing about this in a few days/weeks/months/years since it was funnier than a lot of the other stuff that’s happened.
rofl, lmao, or rotflmao = These used to be a creative way of laughing other than the typical ‘lol’, but generally the only people that use these are complete losers. (Yes, I mean you Nate.) Typically, these LOSERS use these in place of ‘heh’ or ‘hehe’, and sometimes ‘haha’. — However, it is OK to use these if someone else did something stupid and you're laughing at them as a friend. :)
That’s all I can think of right now. I’ll add more stuff later if I forgot any.