Format

Format, in computer science, as a noun, the structure or appearance of a unit of data, such as a file, fields in a database record, a cell in a spreadsheet, or the text in a word-processed document. For example, a file can be stored in the format typical of a certain application, or it can be stored in a more “generic” format, such as plain ASCII text, which contains all the words but little in the way of page-layout specifications. Similarly, the data-storage areas on a disk are arranged in a particular format of tracks and sectors; the fields in a database are laid out in a certain order when they are used for data entry or for generating reports; a cell in a spreadsheet can be designated for a particular format—numeric, character, dollar value, and so on; and the text in a word-processed document is given certain page, paragraph, and character formats.

As a verb, to format text or the contents of a cell in a spreadsheet means to change the appearance of the selected material. To format (or initialize) a disk means to prepare a disk for use. In the formatting process, which is performed by the computer's operating system or a utility program, the storage space on the disk is organized so that it becomes, in essence, a collection of data “compartments,” each capable of being located (addressed) by the operating system so that data can be systematically stored and retrieved. If a new disk is formatted, this organizational information is recorded on it for the first time; if a used disk is formatted, the same process occurs, but any preexisting information is usually lost.