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Blockchain terms

Blockchain

A distributed database system that stores a record of transactions across a network of computers, called nodes. Transaction data is stored in blocks which are validated and added to the chain by miners.

Block

A unit of transaction data that contains header data and data about the transactions within the block. In Ethereum, the block also contains header data for ommer/uncle blocks.

Transaction

A cryptographically signed instruction that updates the state of the blockchain network. The action must be initiated by an externally-owned address, e.g. an account managed by a human. A transaction must be signed by an originating account (sender) and target a specific address (recipient).

Address

The representation of a public key belonging to a particular user. Addresses are essentially contracts that can receive or send transactions on the blockchain. In practice, the address is the hash of a public key (the rightmost 160 bits of a Keccak hash of an ECDSA public key).

Balance

The amount of a token owned by an address.

Ethereum terms

Ethereum

Ethereum is the blockchain-based network composed of all the Ethereum nodes in the EVM.

Ether (ETH)

Ether is the native cryptocurrency of the Ethereum network.

EVM, Ethereum Virtual Machine

The distributed virtual computer that maintains the state of the Ethereum network. All participants (or nodes) in the network agree on and maintain the state of the EVM. Nodes can broadcast a request to execute code on the EVM (called a transaction request), and executing this code changes the state of the EVM.

Account

A data object that contains an address, balance, nonce and other metadata. There are two account types: externally owned (i.e. controlled by a human with the private keys) and contract (i.e. a smart contract deployed to the network)

Smart contract

Smart contracts are programs that run on the Ethereum network. A smart contract consists of code and data that lives at a specific address on the blockchain.

Contract address, contract

A contract is a type of account that's controlled by code deployed to the network.

A contract address is the hash associated with a contract. All tokens have a contract address. This page lists the most common tokens, and their associated addresses.

Internal transaction

An unsigned message carried out by a smart contract. A transaction (initiated by an externally owned account) will trigger a series of internal transactions.

dapp

A dapp, or decentralized application, is an app that's built using the blockchain. Dapps are usually web apps that use the blockchain as part of it's backend.

NFT

An NFT or non-fungible token is a unique token that is tracked and traded on the blockchain. The NFT token standard was introduced by the ERC-721.

Wei

The smallest denomination of ether. 10^18 wei = 1 ether.

gwei

Also known as gigawei. 1 gwei = 10^9 wei, 1 gwei = 10^-9 ETH.

Transfer

Also known as a token transfer. A transaction that transfers ERC-20 (Ethereum) or ERC-721 (NFT) tokens. Transfers represent value exchanged between two accounts.

Allowance

Also known as "access permissions to tokens". Allows a third party to carry out transactions of a given amount with a user's tokens.

Gas

A fee paid in ETH to the EVM network to fund smart contract execution. The EVM measures the consumption of gas and limits the consumption of computing resources. All transactions must include a limit on the amount of gas used to execute the transaction and the fee that may be paid per unit of gas.

Mainnet

The primary public Ethereum network where transactions involving ETH with real-world value occur.

Testnet

Public Ethereum networks used by developers to test smart contracts. Testnets are analogous to staging servers, where Mainnet is production. Most testnets use a proof-of-authority consensus mechanism, while Mainnet still uses proof-of-work, until The Merge.

Node

Also referred to as an RPC node, or an Ethereum RPC node. A server participating in the Ethereum network by running Ethereum client software. Every node keeps a copy of the state of the EVM. These servers are responsible for verifying, validating, and executing computations which are broadcast to the Ethereum network. The Ethereum network is the aggregate of all the Ethereum nodes and their communications.

See the Ethereum docs on nodes for more information.

Node provider

To access the Ethereum network, developers have to connect to a node. While it's possible to run and maintain your own node, most developers prefer to use hosted node service, or a node provider. This allows developers to connect directly to a node via an API key without managing any infrastructure.

Coinbase Cloud offers both private, dedicated nodes, as well as shared access to a pool of nodes at different price points.

Ethereum APIs

Developers interact with Ethereum nodes via APIs. Every node provides a set of JSON-RPC APIs used to read blockchain data and send transactions to the network. These APIs are referred to as the Ethereum JSON-RPI APIs, native Ethereum APIs, or variations of these terms.

There are wrapper libraries available in Javascript, Python, and many other languages to make it easier to use the JSON-RPC APIs. See the Ethereum documentation for more information.

JSON-RPC

The API protocol Ethereum uses. JSON-RPC is a remote procedure call protocol encoded in JSON. JSON-RPC is stateless, lightweight, and can be used with any communication protocol like TCP or HTTP, which makes it ideal for distributed ledger technologies like Ethereum. See the JSON-RPC specification for more information.

Canonical blocks, canonical chain

Blocks, or a series of blocks, that the EVM agrees upon as the real continuation of the Ethereum blockchain.

Ommer blocks, uncle blocks

During the Ethereum mining process, when two valid blocks are published to the blockchain at almost the same time, one block will be added as the canonical block to the blockchain, while the other, now stale block is considered an uncle block or an ommer (gender-neutral term for the sibling of a parent) block. These blocks can be included by newer blocks and receive a partial block reward.

The Merge

"The Merge" refers to the joining of the existing Ethereum Mainnet proof-of-work execution layer with the new proof-of-stake consensus layer. See the Ethereum documentation for more information.

Coinbase Cloud terms

Coinbase Cloud

Coinbase Cloud is Coinbase's suite of blockchain development services, including private and shared RPC nodes and staking infrastructure.

Coinbase Cloud Node

Coinbase Cloud Node is a hosted node provider. Node offers both private RPC nodes and shared RPC nodes with instant API access, with both free-tier and paid options.

Node's shared nodes product with instant Ethereum API access also provides access to Advanced APIs, which supplement the native Ethereum APIs and simplify access to blockchain data..

Advanced APIs

Coinbase Cloud Node's Advanced APIs simplify access to blockchain data by offering data cuts which are hard to get via native Ethereum APIs, and offer aggregated and filtered data in one API call. The Advanced APIs provide access to token balances for accounts, transactions and transfers for accounts, smart contract event logs, and more. See the Advanced APIs overview for more information