The abbreviation "LOL" stands for "Laughing out loud" and means "laughing out loud".
If you want to convey to your chat partner in a quick and uncomplicated way that you find what they have just said particularly funny, you often write "LOL". This is the general abbreviation for "Laughing out loud".
Over the course of time, the abbreviation has become a real all-rounder for chats (and other types of messages). If you want to express LOL in pictures (or underline it), you can also use smilies.
However, LOL should rather not be used with a classic smilie. While the latter is considered a nice gesture, for example to a "Hello!", LOL is considered an actual, loud laugh.
The abbreviation is usually interpreted positively and is not usually interpreted as a rude or negatively tainted laugh.
Rather, "laughing out loud" indicates that both conversation partners are obviously on the same wavelength. The more LOLs are sent and the more honestly they are meant, the higher the probability that a real meeting will take place sometime in the near future.
The significance of this abbreviation should therefore by no means be underestimated. Especially gays who are looking for a relationship appreciate it extremely if their potential partner has a similar sense of humour as they do.
But: of course, in small talk it is usually not enough to rest on one LOL. If you don't want the conversation to get bogged down afterwards, you should ideally also be able to counter.