Exchanges are the primary on-ramps and off-ramps between fiat currency and crypto. Centralised exchanges hold custody of user funds and typically require KYC verification, offering ease of use and liquidity. Decentralised exchanges let users trade directly from their own wallets via smart contracts, preserving self-custody but often with a steeper learning curve. Choosing an exchange involves weighing security, fees, supported assets, regulatory standing, and whether you prefer custodial convenience or self-custody control.