blocktype

Blocktype is a generic term used in computing to denote the specific kind or category assigned to a block of data. The concept appears across multiple domains: storage, file formats, databases, and programming languages. In storage systems and file systems, data is often divided into fixed-size blocks or pages; a blocktype field or metadata indicates its role, such as data block, index block, free-space block, or metadata block. This information helps the system manage layout, integrity checks, and recovery.

In binary and container formats, blocks or chunks carry a type identifier that tells parsers how to interpret the payload. Examples include RIFF chunks or PNG chunks, where the type/name identifies the data contained. Some formats use numerical codes, others short ASCII identifiers, but the purpose is the same: enabling efficient parsing and validation.

In database engines and data stores, blocktype often informs the cache and storage layers about how to process a block. Data pages contain records, index pages contain pointers, and special system pages may store metadata. Correct handling of blocktype is essential for operations like splitting, compaction, and recovery.

In programming contexts, the term is less standardized. Some languages or libraries refer to a block’s type when describing memory blocks, serialization units, or closures, though use varies by platform.

See also: block, chunk, page, box, metadata, file format.