Which type of database consists of a single file?

A flat file database is characterized by its organization into a single file, typically structured in a simple format such as comma-separated values (CSV) or plain text files. This structure allows for straightforward data storage without the complexities of multiple tables and relationships found in relational databases.

In a flat file, all data is stored within a single file, making it easy to read and write but also limited in terms of complex querying and data integrity constraints. This simplicity can be beneficial for certain applications, particularly for smaller datasets where advanced features provided by other database types aren't necessary.

Other database types, such as relational databases, consist of multiple tables related to each other through keys. Distributed databases spread data across multiple locations or systems, and NoSQL databases can take various forms but often involve collections of documents or more complex structures than a single file. The essential characteristic of a flat file database is its single-file storage format, which provides specific use cases where simplicity and ease of access are prioritized.