The data contained in a file can contain identically or similarly formatted information. It can be text, numeric data or commands. Regardless of whether a file is long or short, it is considered a unit during transmission and storage. They can be packetized and transmitted over packet-switched networks, or stored on disks and managed by a file system. They can be retrieved, edited, and stored at any time using the file name.
A distinction is made between open and closed files, and between linear, sequential and temporary files. According to DIN, a file is a summary of digital data to form a subject-related unit of one or more data records (record groups).