'vanity' is a word that means: when someone thinks that they themselves are very important.
'vanity plate' is an expression for a license plate where someone has a special word or words on it. You have to pay extra to get a vanity plate on your car.
This blog is mainly to explain a different English language expression every day. Sometimes I post other stuff. I also have a YouTube channel which is mostly about computer software: https://www.youtube.com/englishspacedog
