Wallet basics: hot, cold, and custodial
What a crypto wallet actually holds, how hot vs cold storage differ, and why custodial apps are not the same as keys you control.
A “wallet” in crypto is less like a leather billfold and more like a keyring. The coins live on a blockchain; your wallet holds the private keys (or a seed that derives them) that prove you can move those coins. Public educational references such as the Bitcoin.org and Ethereum.org wallet guides describe the same idea: possession of keys, not a branded app icon, is what matters for self-custody.
Three common shapes
- Hot wallets — software that stays connected (browser extensions, phone apps). Convenient for small amounts you use often; more exposed to malware and phishing.
- Cold wallets — hardware devices or carefully air-gapped setups that keep private keys offline for signing. Better for long-term storage when set up correctly (see manufacturer docs such as Ledger and Trezor support libraries).
- Custodial wallets / exchange accounts — a company holds the keys. You see a balance in an app, but withdrawals depend on that company’s policies and security. Useful for learning interfaces; not self-custody.
What you actually back up
Most modern wallets give you a seed phrase (BIP-39 recovery words). That phrase can recreate the keys. Treat it like the master key to every account derived from it. Official BIP-39 documentation and wallet vendor recovery guides stress: write it offline, never type it into a random website, never photograph it for cloud photos.
Practical habits (education, not a product pitch)
- Start with a reputable wallet’s own docs; verify the download URL from the project’s official site.
- Keep only what you need for day-to-day activity in a hot wallet.
- Test a small recovery on a spare device before you trust a large balance to a backup.
- Know whether you are self-custodial or relying on a custodian—the risk model is different.
Related free docs
- Seed phrase safety checklist
- Hot wallet hygiene checklist
- What is a token approval?
- Crypto glossary in plain English
Sources
- ethereum.org — Wallets
- bitcoin.org — Choose your wallet
- BIP-39 — Mnemonic code for generating deterministic keys
Educational content only — not investment advice. Ascent Advisors does not tell you which wallet brand to buy or which assets to hold.