Blocks

Blocks are solid, typically rectangular units used in construction, manufacturing, and everyday play. They are designed to be stacked, joined, or arranged to form larger structures or modular components. Although sizes and materials vary, blocks share the property of being portable and easy to handle.

Construction blocks include concrete blocks, often called cinder blocks, which form walls and foundations. Concrete blocks are typically hollow to reduce weight and allow insulation. Other varieties include autoclaved aerated concrete (AAC) blocks and clay or foam blocks, each chosen for strength, thermal performance, or fire resistance. Blocks are usually laid with mortar and may be reinforced with steel.

Block-based programming describes software development using draggable blocks that fit together to form commands. This visual approach, used by environments such as Scratch and Blockly, lowers barriers to programming and emphasizes modularity and data flow. It is well suited for education and rapid prototyping but can limit expressiveness for complex software.

In distributed systems and cryptocurrencies, a block is a data container that records a set of transactions and metadata such as a timestamp and a link to the previous block’s hash. Blocks are proposed or mined under consensus rules, grouped into a chain, and restricted by size and validation rules to ensure security and throughput.

Beyond physical and digital blocks, the term also denotes city blocks—sections of a street grid bounded by roads—and blocks of memory or storage in computing, indicating fixed units used for organization and allocation.