Computer file is a collection of electronic data, used to organize the storage and processing of data by computer. The file is the basic unit of storage for computer information. Computers store written documents as text-only files. Database files contain a series of organized records. Pictures are stored as graphics files, and sounds as audio files. Even the instructions that tell the computer what to do reside in a file. Such files are called executable files, because the computer executes (carries out) the instructions.