Blocky saysWallets are custodial (someone holds your keys) or non-custodial (you do).
A custodial wallet (an exchange like Coinbase) holds your private keys for you — convenient, recoverable, but you trust them and they can freeze/lose funds ("not your keys, not your coins"). A non-custodial wallet (MetaMask, hardware) means you alone hold the keys — full control and self-responsibility, no reset if you lose them. The choice is a trust-vs-control trade-off.
Power-ups you unlock
Custodial: a third party holds your keys
Non-custodial: you hold your keys
Custodial = convenient but trust-dependent
Non-custodial = control + full responsibility
Double-Spend Dan attacks — common mistakes
Assuming exchange balances are "yours" unconditionally
Going non-custodial without secure key backup
Confusing the two models’ recovery options
Boss battleState the trade-off captured by "not your keys, not your coins".
Example code
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<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre>custodial: exchange holds keys (recoverable, trust them)
non-custodial: you hold keys (full control, no reset)</pre></body></html>