What Is the Mempool?

Everyone who has used bitcoin has also used the mempool, or rather a mempool, as there isn't just one. But what is the mempool?

Well technically, there is no such thing as “the” mempool. Every individual full bitcoin node operates its own mempool, a cache of valid bitcoin transactions that have been broadcast to the network but have yet to be confirmed in a block. Nodes exchange messages with each other to see what transactions they have or not, and exchange ones they don’itemize