A file is a self-contained piece of information that is stored on a computer storage device, primarily identified by its filename. It is an object on a computer that stores data, information, settings, or commands used with a computer program. Files can be shared with and transferred between computers and mobile devices via removable media, networks, or the Internet. Different types of computer files are designed for different purposes. A file may be designed to store an image, a written message, a video, a program, or any wide variety of other kinds of data. Certain files can store multiple data types at once.

There are three types of files in a computer: application files, data files, and system files. Application files are files that are used to run a specific program, data files are files that contain data or information, and system files are files that are used by the operating system to run the computer.

Files are typically organized in a file system, which tracks file locations on the disk and enables user access. A folder holds one or more files, and a folder can also contain other folders, and there can be many levels of folders within folders. Folders provide a method for organizing files much like a manila file folder contains paper documents in a file cabinet.

Files are created using a computer program. For example, to create a text file, you would use a text editor; to create an image file, you would use an image editor; and to create a document, you would use a word processor. Computer files are stored on a drive (e.g., the hard drive), disc (e.g., DVD), and a diskette (e.g., floppy disk), and may be in a folder (directory) on that medium. When saving a file to your computer, you are saving the file to the hard drive.

In summary, a file is a container in a computer system for storing information, and it can be used to store different types of data. Files are organized in a file system, and they can be created using a computer program. Folders provide a method for organizing files.