A marketing tactic in which a crypto company sends coins of their currency into the wallet address of a member of a blockchain at no charge, to raise awareness of their currency.


The fundamental basis of cryptocurrency. A blockchain is a digital ledger of transactions stored simultaneously on multiple nodes of the same network. Unlike traditional financial institutions, this decentralized approach allows for rapid, anonymous transactions while providing complete security. As of 2023, there are over a thousand different blockchains online, including Ethereum, Avalanche, and Polygon.


To remove coins from circulation permanently and prevent them from being traded (see also Mint).


See blockchain


A cryptocurrency (such as USDC) running on a particular blockchain, or a single unit of that currency. (See also Token)


The legal capacity of a financial institution or individual to retain and safeguard a user’s assets to keep them from being stolen or lost.

Ether (ETH)

The cryptocurrency token used on the Ethereum platform.


A cryptocurrency; the second largest (by market capitalization) after Bitcoin.

EVM (Ethereum Virtual Machine)

A virtual machine that executes code in a precise manner to create every smart contract [on Ethereum].


A system that rewards users in crypto coins for completing certain tasks. In development, this also refers to a resource that issues coins of no monetary value to be used for testing purposes.


A transaction fee is imposed by the Ethereum network. In most cases, users pay this fee, though developers can pay it to make a transaction more appealing to customers.


To generate new coins and put them into circulation to be traded (see also Burn).


A non-fungible token is a digital collectible that uses the crypto ledger technology to identify its sole owner. An NFT can be any digital file but often takes the form of an image file containing a unique visual artwork.


Describes any transaction that takes place on a blockchain and is stored on the distributed public ledger.

Primitive (noun)

The basic building block of a computer language. In the context of Programmable Wallets, the term describes fundamental data types used to describe such a wallet: users, wallets, wallet sets, etc.

Private key

The encrypted password that safeguards a user’s crypto holdings. This takes the form of a data string of letters and numbers 64 characters or longer. A user must present a private key to authorize a transaction. Translated to the world of traditional finance, the private key could be compared to a personal signature or PIN code.

Public key

The public-facing address of a user’s crypto wallet that must be shared to receive funds into an account. Every wallet has both a private key and a public key. Translated to the world of traditional finance, the public key could be compared to an account number or ATM card.

Smart contract

A contract on the blockchain is facilitated, verified, or enforced automatically via a computer protocol, with no third-party approval or interaction required.


A currency whose value directly mirrors that of another currency, commodity or financial instrument to provide users with a fixed, unchanging market value. Circle’s own stablecoin is USDC, which reflects 1:1 the current value of the US dollar.


An alternative blockchain used for testing by developers. It operates like a standard blockchain, but the transactions it supports do not transfer actual currency.


A cryptocurrency running on a particular blockchain, or a single unit of that currency. (See also Coin)


Circle’s own stablecoin, which always reflects 1:1 the value of the US dollar and can always be exchanged for equivalent US dollars.


A digital storage device to safeguard a user’s crypto assets (coins or NFTs). Though often thought of as being software-based only (as in Programmable Wallets), wallets can also take a physical form if a user wishes to safeguard assets by keeping them offline.

Wallet address

Similar to a public key but also different. The wallet address specifically identifies a destination for a cryptocurrency transaction, while a public key serves to facilitate such a transaction.