Wallet basics
Keys, custody, and the question that decides everything — who can actually move your crypto?
A crypto wallet does not store coins. It stores keys — and whoever holds the key controls the asset. Every custody decision you will ever make comes down to one question: who holds the key?
Custodial: the exchange holds the key
When you buy on an exchange and leave the balance there, the exchange holds the keys. You hold a claim against the exchange — closer to a bank balance than to owning bitcoin. This is convenient: no backups, familiar password resets, easy selling. The cost is counterparty risk. If the exchange freezes withdrawals or fails, your claim waits in line with everyone else's.
Self-custody: you hold the key
A self-custody wallet generates a private key that only you control, usually backed up as a 12 or 24-word recovery phrase. Nobody can freeze it, and nobody can restore it for you either. Lose the phrase and the assets are gone; anyone who copies the phrase owns everything the moment they type it in.
Two rules do most of the protective work:
- Never type a recovery phrase into a website, a message, or an app that asked for it. Legitimate software asks only during a restore that you started yourself.
- Test small first. Send a small amount, confirm it arrives, then move the rest.
Hot and cold
A hot wallet lives on an internet-connected device — convenient, but exposed to whatever malware your device catches. A cold (hardware) wallet keeps the key on a separate device that signs transactions without revealing it. The usual pattern: hot wallet for small, active amounts; cold storage for anything you would mind losing.
Choosing for now
Starting out with small amounts on a reputable exchange is a defensible choice — convenience has real value while you learn. The mistake is not choosing custodial; it is not knowing you chose it. From the moment your balance stops feeling small, the next lesson in this tree — choosing a safe route — is about moving deliberately, not urgently.
