> ## Documentation Index
> Fetch the complete documentation index at: https://docs.amberdata.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Blocks

# Definition

In a blockchain, a block is a collection of verified transactions that are bundled together and added to the blockchain in sequential order. Each block contains a block header and block data. The block header contains metadata about the block, such as a timestamp, a unique identifier (known as a "hash"), and a reference to the previous block in the chain. This reference to the previous block creates a chronological link between blocks and helps ensure the integrity of the blockchain.

The data in a block is the actual set of transactions that are being added to the blockchain. These transactions include things like sending cryptocurrency from one wallet to another, executing a smart contract, or adding a new asset/token to the blockchain. The block data is represented as a digital ledger, which includes information about the sender, receiver, asset amount(s), and other relevant details. Once a block is added to the blockchain, it becomes a permanent and unalterable record that can be verified by anyone on the network.

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# Details

Block data depends on the specific blockchain network, but example information includes:

* **Block details**: Information about each block in a blockchain network, including its hash, timestamp, size, and transaction data.
* **Transaction data**: Detailed information about transactions in a blockchain network, including sender and receiver addresses, gas used, and transaction fees.
* **Token data**: Data on tokens in a blockchain network, including token balances, supply, and transaction history.
* **Contract data**: For smart contract-based blockchains, we offer data on the contracts themselves, including contract address, source code, and contract events.
* **Address data**: Data on addresses in a blockchain network, including balances, transaction history, and token holdings.
* **Network data**: Data on various network metrics, such as network hash rate, difficulty, and mining rewards.

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# API Endpoints

[/blockchains/blocks/metrics/historical](/http/blockchain/metrics-historical--confirmed-blocks)

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# Availability

Blockchain endpoints across the various On-Chain namespaces are accessible via **REST API**, **WebSockets**, and **JSON-RPC**. A comprehensive list of supported blockchain networks is available in the [API Documentation](#).

Amberdata enables access to all events from the genesis block onward. This infrastructure allows for the delivery of complete historical datasets across most supported blockchain protocols.

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# Frequently Asked Questions

#### **What is the value of showing block data compared to address and transaction data?**

Exposing block-level data in addition to address- and transaction-level data provides flexibility in how blockchain data is queried and analyzed.

* For **high-level overviews**, such as total transaction count or cumulative gas usage within a block, the **block transactions endpoint** is more efficient.
* For **granular analysis**, such as inspecting individual transaction inputs, outputs, or decoded logs, the **transaction hash endpoint** offers greater detail.

This multi-level access supports a wide range of use cases—from macro-level network analysis to low-level protocol debugging or compliance auditing.

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