Coinbase Wallet is a self-custody wallet that gives you complete control of your crypto. This means that the private keys (that represent ownership of the cryptocurrency) for your Wallet are stored directly on your mobile device and not with a centralized exchange like Coinbase.com.
The Metamask enables the users to manage and safely store the transactions, account keys, cryptocurrencies along with the tokens. With the help of a MetaMask Sign In account, you can easily use the Metamask account to connect with decentralized apps or Dapps along with a compatible web browser.