Block

A block is a collection of transactions that have been verified and added to the blockchain. Each block typically contains a cryptographic hash of the previous block, a timestamp, and a list of transactions. Once a block is added to the blockchain, it cannot be modified or deleted, ensuring the integrity of the entire transaction history. This immutability is one of the core properties that makes blockchain technology trustworthy.

Blocks are created at regular intervals depending on the network. Bitcoin, for example, targets a new block roughly every ten minutes, while Ethereum produces blocks much more frequently. Each block has a maximum size or gas limit, which determines how many transactions can be included. During periods of high network activity, blocks can fill up quickly, leading to higher transaction fees as users compete to have their transactions included.

For algorithmic traders, block dynamics matter in several ways. Transaction confirmation speed depends on how quickly your transaction is included in a block, which affects arbitrage windows, order execution timing, and on-chain settlement. Understanding block times and mempool conditions helps traders set appropriate gas prices or fees and anticipate delays that could impact strategy performance.