A filename is the name given to a computer file to identify its contents. There are several synonyms to filenames, such as file identifier, file name extension, file name, file handle, file type, and file signature. Each of these synonyms has a specific meaning related to the technical details of the file, such as its format, content, and location. For instance, a file type refers to the format of the file, while a file identifier describes a unique number assigned to the file. The different synonyms for filenames can be used interchangeably in technical documentation, programming, and computing to refer to the various aspects of files.