What is the difference between Coinbase & metamask?

I'm curious to know, could you please explain the fundamental differences between Coinbase and MetaMask? As someone who's interested in cryptocurrency, I've heard about both of these platforms but I'm not entirely clear on how they differ from each other. Coinbase, I understand, is a popular cryptocurrency exchange, but what role does MetaMask play in the crypto ecosystem? Are they both used for similar purposes or do they serve distinct functions?