Custody vs Non-custodial
Plain English
Custody means someone else (like Coinbase) holds your crypto for you, similar to a bank holding your money. Non-custodial means you control your own keys and crypto directly. Custody is easier but you trust the company. Non-custodial gives you full control but more responsibility.
Technical
Custodial services hold and manage private keys on behalf of users, providing convenience and support but introducing counterparty risk and loss of sovereignty. Non-custodial (self-custody) solutions give users direct control over private keys, enabling true ownership and eliminating third-party risk, but requiring users to manage security and recovery themselves.