A cryptocurrency exchange is a platform or marketplace where individuals can buy, sell, or trade cryptocurrencies like Bitcoin, Ethereum, or Litecoin for other digital currencies or traditional fiat currencies like the US dollar.

Cryptocurrency exchanges facilitate:

1. _Trading_: Buying and selling cryptocurrencies.

2. _Exchange_: Swapping one cryptocurrency for another.

3. _Conversion_: Converting cryptocurrencies to fiat currencies or vice versa.

Types of cryptocurrency exchanges:

1. _Centralized Exchanges_ (CEXs): Traditional exchanges, like Coinbase or Binance, that operate like stock exchanges.

2. _Decentralized Exchanges_ (DEXs): Peer-to-peer platforms, like Uniswap or SushiSwap, that operate on blockchain networks.

3. _Hybrid Exchanges_: Combine elements of CEXs and DEXs.

Cryptocurrency exchanges offer various features, including:

1. _Wallet services_

2. _Price charts and analysis tools_

3. _Security measures_ (e.g., two-factor authentication, cold storage)

4. _Customer support_

5. _Mobile apps_