Block weight is a measure used to determine the size and complexity of a block within a blockchain. It accounts for both the transaction data and the associated metadata, such as signatures and scripts. The concept of block weight emerged to address limitations in block size and to optimize network efficiency. Instead of using a simple byte-sized limit, block weight allows for a more nuanced approach.

It enables networks to handle various types of transactions, which can have different resource requirements. For example, transactions that require more complex computations may weigh more heavily on the network than simpler ones. By considering these differences, block weight helps maintain a balance between transaction throughput and security.

This approach is crucial for ensuring that the network remains scalable and can handle increased usage without compromising speed or security. Overall, block weight helps to enhance the functionality and robustness of a blockchain system while managing resource allocation effectively.