While it means "laugh out loud", it's sometimes tagged onto the end of a sentence, to mean it's just a joke, sarcasm or lighthearted comment. One problem with text communication is that a clever or witty comment can be taken at face value. So for example, "your an idiot lol" is a gentle tease, not an insult. Or, "i dont really care lol" means perhaps I do care, but don't take me too seriously. Some people use it excessively, and it makes them seem high-strung.

It doesn't actually mean anything. I doubt that more than one percent of the people that use it are actually laughing out loud. And giggles, smiles and snorting wouldn't count as a laugh. So it has ended up as it started, a cutesy internet slang for those that live in an alternate world called cyberspace.

"lol" is used to mean "laughing out loud" but nowadays this abbreviation refers to "lots of laughs".

Actually, when I use "lol," I am very rarely laughing. Sometimes I use "lol" simply to indicate that I find something that a chatter said amusing or ironic. Sometimes I also use "lol" to let the other person know that something I say is to be taken in jest, or carries a sarcastic tone. For example, if an American says "Actually, my Chinese is better than my English, lol." Here, his "lol" indicates that he is just kidding. I may reply, "lol, mine too." Here, I use "lol" to indicate two things: 1) what the American said was amusing, and 2) I am also kidding (not serious).

哈哈，呵呵，嘻嘻，恩，这样的，。。。你们为什么总是那样聊天啊？哈哈