Internet Slang

LOL means "laughing out loud," or sometimes "laugh out loud." It originated on a 1980s era bulletin board system named Viewline where a user first responded to a message to indicate laughter in real life.

NSFW stands for "not safe for work," and is usually applied to pornographic material, however it can also be more tame things someone feels isn't appropriate to view or download where they are employed.

If a person was to slide into someone's DMs or "direct messages", it means they are messaging them with romantic or sexual intent. This is an especially prevalent acronym on Instagram where people often direct message others based on their looks.

The term "catfishing" originated from the 2010 documentary "Catfish", which chronicled the story of an online relationship built on a web of lies. The term is now used to describe the act of creating a fake online persona to deceive someone, often in a romantic context. Being "catfished" refers to being the one deceived. 

TL;DR stands for "too long; didn't read" and is used to indicate that a summary of an overly long post is given following the acronym. This originated on Reddit where some posters can get carried away with their stories and needed to succinctly summarize their issues.