What does "LOL" stand for in online conversations?

What does "BRB" mean in chat messages?

What does "TBH" mean in social media posts?

What does "IDK" stand for?

What does "BTW" mean in a conversation?

What does "OMG" express in online chats?

If someone types "JK," what does it mean?

What does "TBT" mean when people post old photos?

What does "HBD" stand for in birthday messages?

What does "BFF" mean when talking about friends?