Decentralised Exchange
An exchange is a platform where you can buy, sell or trade cryptocurrencies without a central power or service provider.
Quick Reference:
Peer to Peer. Trade Coins/Tokens. Wallet Required.
Expanded Explanation:
Exchanges are the main gateways into crypto. Decentralised exchanges, known as DEX, allow users to trade directly from their wallets without intermediaries. DEX provide far more control but with that control responsibiltity over ones asset increases.