Before we get in the types of wallet, let see what is a wallet in crypto. Wallet is stores all of your crypto currency like: Bitcoin, Ethereum, etc… If you want to transaction a currency or hold some currency, you need to have a wallet. Wallets have two keys, private key and public key, public key is like your credit card number, if someone wants to send you some currency you should give them only and only your public key ,they do not need another thing and your private key is like your credit card password, you should not share it with anyone.