What Is a Bitcoin Wallet?

Every Bitcoin wallet starts from a secret: a private key, or in modern wallets a seed from which many private keys are derived. From the private key the wallet computes a public key, and from the public key it computes the addresses you share with people who want to pay you. Anyone can send bitcoin to an address. Only the holder of the matching private key can spend it.

When you send bitcoin, the wallet builds a transaction that references the coins you control, states where they should go, and signs it with your private key. The signature is what the network verifies. Once nodes accept the transaction it enters the mempool, and a miner eventually includes it in a block. The wallet then watches the network to show you balances and history, usually by asking servers about the addresses it knows are yours.

Almost all modern wallets follow open standards for this. BIP-39 defines the recovery phrase (12 or 24 words) that encodes the seed. BIP-32 defines how one seed derives a whole tree of keys. BIP-84 defines the Native SegWit address type that starts with bc1q. A wallet built on these standards can be restored in any other wallet built on the same standards, which is exactly what protects you if the app you use disappears.

The 12 or 24 words a wallet shows you when you create it are not a password. They are the seed itself, written in a human-readable form. Whoever holds those words holds the bitcoin, on any device, with any compatible wallet, forever. Losing them means losing access; leaking them means losing the funds.

This is also where language matters more than people expect. The BIP-39 standard defines wordlists in several languages, but nearly every wallet only shows the English list. If English is not your first language, you are asked to copy, verify and safeguard twelve unfamiliar words, and a single misread letter can make a backup unrestorable. TZUR was built around this problem: it generates and restores the recovery phrase in 31 languages, always alongside the English version, and both derive from the same seed so the result stays fully BIP-39 compatible.

• Write the phrase on paper or metal, never in a screenshot, a note app, or cloud storage.
• Verify the backup by restoring it before you move real money.
• Keep the English version as well if you plan to restore in a wallet that only accepts English.
• Never type your phrase into a website, a form, or a support chat. No legitimate wallet will ask.

The most important distinction is who holds the keys. In a custodial wallet, such as an exchange account, a company holds the private keys and lets you log in with an email and password. It feels like a bank: convenient, recoverable, and entirely dependent on that company staying solvent, honest, and online. If it freezes withdrawals, gets hacked, or is ordered to stop serving your country, your bitcoin goes with it.

In a self-custody wallet the keys are generated on your own device and never leave it. Nobody can freeze the funds, block a payment, or lose them on your behalf. The trade-off is responsibility: there is no password reset. Your recovery phrase is the only way back. Self-custody is what Bitcoin was designed for, and it is the model TZUR uses. If you want the reasoning in depth, read our guide to self-custody Bitcoin wallets.

Wallets are also grouped by how connected the keys are. A hot wallet keeps keys on an internet-connected device such as a phone or laptop, which makes everyday spending easy. A cold wallet keeps keys offline, on a hardware device or on paper, and only signs transactions when you deliberately connect it. Hardware wallets are cold wallets in a purpose-built device; they are the standard choice for large long-term holdings.

A well-built mobile wallet sits in between. TZUR for iPhone, for example, generates keys on the device and stores them in the hardware-backed iOS Keychain, restricted to that device and excluded from backups, signs every transaction locally, and can be locked with Face ID or a PIN. It is still a hot wallet, so the sensible pattern is the one most bitcoiners use: a mobile wallet for the amounts you actually spend, and cold storage for the rest.

Many popular wallets support hundreds of coins and tokens. That breadth comes with a larger codebase, more integrations, more update pressure, and more ways for something to go wrong. A Bitcoin-only wallet does one thing and can do it carefully. TZUR is Bitcoin-only by design: no altcoins, no tokens, no swaps, no trading. We explain the reasoning in our note on why a Bitcoin-only wallet.

You do not need to be an expert to pick a good wallet. You need honest answers to a short list of questions, ideally found on the wallet's own site rather than in marketing copy.

• Who holds the keys? If the answer is a company, it is custodial.
• Is the recovery phrase a standard BIP-39 phrase you can restore elsewhere?
• Are keys generated and kept on the device, and are transactions signed locally?
• Does it require an account, email, or identity verification? A self-custody wallet should not.
• Can you verify payments yourself? TZUR includes the BlockSight.Live block explorer inside the app so you can check a transaction without leaving the wallet or trusting a third-party website.
• Is the business model clear? TZUR is a one-time purchase with no subscription and no hidden monetization, so you know who the customer is.
• Who is behind it, and can you check? Look for a legal entity and a way to contact it.

TZUR is a Bitcoin-only, self-custody wallet for iPhone, with a native Android version in final testing. It follows BIP-39, BIP-32 and BIP-84, uses Native SegWit addresses with Taproot send support, and is the first wallet that generates and restores the recovery phrase in 31 languages. The BlockSight.Live explorer is built in. It is built by BlockSight OÜ, a registered company in Estonia, and sold as a one-time purchase of $59.99 on the App Store. If you are new to bitcoin and want a wallet that speaks your language, that is the problem it was built to solve.