Bitcoin glossary: the terms used on CoinCorner, in plain English
This glossary defines the Bitcoin, Lightning, custody and regulatory terms used across CoinCorner in one or two sentences each, with a link to the guide or product page where the term matters. A satoshi, for example, is the smallest unit of bitcoin: one bitcoin equals 100,000,000 satoshis.
All 24 terms, A to Z
Each entry gives the definition first, then the page where the term matters. These are the words you meet on the CoinCorner Bitcoin exchange, in its apps and in the guides in the learn hub.
Bitcoin basics
Four terms explain what you own and how it moves. Bitcoin is counted in satoshis, moved by transactions that the network records, paid for with a network fee and controlled by whoever holds the private key.
Satoshi (sat)
A satoshi, or sat, is the smallest unit of bitcoin: one bitcoin equals 100,000,000 satoshis. The unit is named after Bitcoin's pseudonymous creator, Satoshi Nakamoto. Small amounts are easier to read in sats than as long decimals of a bitcoin. The guide to buying Bitcoin in the UK covers the smallest amount you can buy.
On-chain transaction
An on-chain transaction is a Bitcoin payment recorded on the blockchain, the public record of transactions shared between all Bitcoin users. It waits to be included in a block, and a new block is added roughly every 10 minutes on average. A withdrawal to a Bitcoin address is on-chain: see how to send Bitcoin to your own wallet.
Network fee
A network fee is a small amount of bitcoin paid by the sender so that miners include the transaction in a block. It is not fixed and tends to be higher when the network is busy. At CoinCorner, receiving Bitcoin is free and sending costs the network fee shown on the platform; other charges are in CoinCorner's fee schedule.
Private key
A private key is a secret piece of data that proves the right to spend the bitcoins in a specific wallet. Anyone who has the key can spend the coins, so it must never be revealed. When a company keeps keys for its customers, how it stores them matters: see how CoinCorner holds its keys.
Buying and stacking
These are the words you meet between opening an account and placing an order: the identity check at the start, the cost that sits inside a price, and two names for buying a little at a time.
Stacking sats
Stacking sats means building up a holding of bitcoin in small, regular amounts, counted in satoshis. It is slang from the Bitcoin community for a habit, not a product, and it carries no promise of profit. CoinCorner uses the word for its Stacking Accounts, sub-accounts with personal goals, described with Stacking Accounts and recurring buys.
Pound-cost averaging (DCA)
Pound-cost averaging, known elsewhere as dollar-cost averaging or DCA, means buying a fixed amount of an asset at regular intervals instead of all at once. The price you pay averages out over time; the risk of loss remains. On CoinCorner a recurring buy runs by standing order from your bank, daily, weekly or monthly: set up a recurring Bitcoin buy.
Spread
The spread is the gap between the price a service sells an asset for and the price it buys it back for at the same moment. It is a cost of trading even where no separate fee is shown. CoinCorner's main site does not publish its buy and sell spread; the published charges are under fees and spread.
KYC (identity check)
KYC, short for know your customer, is the identity check a financial firm must complete before it opens an account for you. It is part of the rules against money laundering. CoinCorner asks for valid ID and proof of address, and you must be over 18. Documents and timings are covered in the frequently asked questions.
Lightning
Lightning is a payment network built on top of Bitcoin for small, fast payments. Six terms cover the network, the channels it is made of, three ways to ask for a payment and the card that pays with a tap.
Lightning Network
The Lightning Network is a protocol for making fast Bitcoin payments through a network of payment channels. Payments pass between channel partners without each one being recorded on the blockchain, which suits small and frequent amounts. Opening and closing a channel are on-chain transactions. The guide to the Lightning Network explains it step by step.
Payment channel
A payment channel is an amount of bitcoin that two participants lock up on the Bitcoin network and can spend only with both their signatures. They pay each other by signing a new split of that amount. Channels connect, so a payment can reach someone you share no channel with: read how Lightning channels join into a network.
Lightning invoice
A Lightning invoice is a request for one payment over the Lightning Network, usually shown as a QR code. The BOLT 11 specification sets its format, which tells the payer's wallet where the payment goes and what it is for. Businesses that take Lightning payments in a shop show a fresh invoice at the till for each sale.
Lightning address
A Lightning address is a reusable payment identifier written like an email address, in the form name@domain. A wallet that supports it fetches a payment request from that domain, so the payer needs no new invoice each time. It is defined in the LNURL document LUD-16. The Lightning guide explains how a Lightning address differs from an invoice.
LNURL
LNURL is a set of open specifications that let a Lightning wallet and a service arrange a payment through a link, QR code or tap. Each part is a numbered document, or LUD: LUD-06 covers paying, LUD-03 withdrawing and LUD-16 the Lightning address. Wallets and services support different sets. The guide shows what LNURL adds to Lightning payments.
Bolt Card
The Bolt Card is an NFC contactless card that pays over the Bitcoin Lightning Network using LNURL. A tap at a merchant's point of sale makes the payment. It is set up as either a debit card linked to a CoinCorner account or a gift card, and costs £4.99 per design: see how a Bolt Card tap pays over Lightning.
Custody and security
Whoever holds the keys controls the Bitcoin. These five terms describe who holds them, how they are kept and protected, and one statement that CoinCorner makes about customer assets.
Custody and self-custody
Bitcoin custody means a company holds the private keys that control your Bitcoin on your behalf; self-custody means you hold those keys yourself. With custody, the custodian's security and solvency are your risk. With self-custody, losing the key is. CoinCorner holds the keys for its accounts; the Vault adds a second key holder: see Bitcoin custody in the CoinCorner Vault.
Multi-signature (multisig)
Multi-signature, or multisig, is a wallet set-up in which more than one private key must sign before Bitcoin can move. Because the keys sit in different hands, one stolen key cannot spend the coins. In the CoinCorner Vault the keys are held by CoinCorner and AnchorWatch across multiple jurisdictions: see multi-signature Vault custody.
Cold storage
Cold storage means keeping the private keys that control Bitcoin offline, on devices that are not connected to the internet. Keeping keys offline reduces their exposure to online attacks, at the cost of slower access. CoinCorner says it holds its keys offline in cold storage and in multi-signature wallets: see cold storage and account security at CoinCorner.
Two-factor authentication (2FA)
Two-factor authentication, or 2FA, is a second check when you sign in, on top of your password, usually a one-time code from your phone. With it, a stolen password alone does not open the account. 2FA is available on CoinCorner accounts, and the FAQ explains how to turn on two-factor authentication.
Full reserve
Full reserve means a custodian holds all of its customers' assets one for one, without lending them out or keeping only a fraction. It is a description, not a regulatory status. CoinCorner states that customer assets are "always held in full reserve" and publishes no proof-of-reserves report or audit: see how CoinCorner holds customer Bitcoin.
Regulation and money
Registration, authorisation and compensation are different things, and they apply to different parts of an account. Bitcoin services sit under one set of rules, and pound and euro balances under another.
These five definitions paraphrase the regulators' own pages, which are listed under the sources below.
Designated business (Isle of Man)
A designated business is a firm registered with the Isle of Man Financial Services Authority under the Designated Businesses (Registration and Oversight) Act 2015. CoinCorner Ltd is one (register entry), on the register since 4 May 2016. Such firms are "registered and overseen by the Authority for AML/CFT compliance only", which is not a licence: see designated business registration explained.
FCA registration and authorisation
FCA registration is the anti-money-laundering registration that firms providing in-scope cryptoasset services in the UK need before they start trading. Authorisation is a separate, fuller permission under the new cryptoasset regime, expected on 25 October 2027; registration does not convert into it. CoinCorner states that it is not regulated by the FCA: see the guide to UK Bitcoin regulation.
E-money
E-money, short for electronic money, is money stored electronically, usually in an online account or wallet or on a prepaid card. You can use it to pay for goods and services. At CoinCorner it is issued by Mercury Foreign Exchange Limited, which is authorised by the FCA under the Electronic Money Regulations 2011, FRN 900858: see who issues CoinCorner e-money.
Safeguarding
Safeguarding is the duty of an e-money institution to protect customers' money, in a separate account with a bank or under insurance or a similar guarantee. It applies in place of FSCS cover if the provider fails. CoinCorner states that e-money funds are held in segregated accounts and safeguarded: see how pound and euro balances are held.
FSCS
The FSCS, the Financial Services Compensation Scheme, is the UK scheme that can pay compensation to customers of authorised financial services firms that have failed. It does not protect Bitcoin or other cryptoassets held with CoinCorner, and it does not cover e-money, which is safeguarded instead. The regulation guide explains whether the FSCS covers Bitcoin held with a firm.
Sources for these definitions
Definitions were checked against these public sources in October 2026. Statements about CoinCorner come from its own pages (home, buy Bitcoin, recurring buys, Vault and Bolt Card), read on .
- bitcoin.org, Vocabulary: https://bitcoin.org/en/vocabulary
- Lightning specifications (BOLTs), introduction: https://github.com/lightning/bolts/blob/master/00-introduction.md
- BOLT 11, Invoice Protocol for Lightning Payments: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
- LNURL documents (LUDs): https://github.com/lnurl/luds
- Isle of Man Financial Services Authority, designated business overview: https://www.iomfsa.im/designated-business/dnfbp-overview/
- Financial Conduct Authority, registration ahead of the new cryptoasset regime: https://www.fca.org.uk/firms/new-regime-cryptoasset-regulation/registration-under-mlrs-ahead-new-fsma-regime
- Financial Conduct Authority, new regime for cryptoasset regulation: https://www.fca.org.uk/firms/new-regime-cryptoasset-regulation
- Financial Conduct Authority, using payment service providers: https://www.fca.org.uk/consumers/using-payment-service-providers
- Financial Services Compensation Scheme, about FSCS: https://www.fscs.org.uk/about-us/
Put the words to use
The buying guide walks through opening an account, the identity check, a first purchase and where to keep Bitcoin afterwards, using the terms defined on this page.