Originally created as an acronym for Laugh Out Loud, used mostly in internet chat rooms and online video games to express amusement, usually in response to a statement or joke made by another.
In the current
day however, it has been massively overused and now basically means "I am too
lazy to think of anything worthwhile to respond". Lol is also commonly used as a sentence
filler, replacing periods or simply trying to make the statement not seem to serious. Unfortunately, it is not hard to fall into a habit of using it as the filler.
Now a days when
people want to express actual amusement at a statement
like lol originally meant, they will usually just spell out "haha" or enhance lol with an explanation point or multiple "L"
s and "O"s.