I saw some people getting confused with those prefixes so here:

WTS- Want To Sell
Use this prefix when you have something you want to sell ex: minecraft accounts

WTB- Want To Buy
Use this prefix when you are looking to buy something specific ex: an OG minecraft account

WTT- Want To Trade
Use this prefix when you are looking to trade something for something else ex: you have a minecraft account and you want to trade it for a game

PS: I added WTS just because i had to put a prefix