Can someone give a brief explanation of what DeFi is
It's hard to explain it in simple terms but you can read an article[1] which is something like this.[1] What Is DeFi?
what are your top 5 coins/tokens
I don't have a top 5 this time but I'll share to you the first two that I'm currently in but the other coins that I'll say are also considerably good.1. Btc - long
2. Eth - long
3. Ltc
4. Bnb
5. Dot
where do you usually trade it. Thanks! 
Binance. You're welcome!