What is Digital File?

Digital File: Simple Definition

A digital file is any collection of data stored on a computer, phone, or other digital device. Files can contain text, images, video, audio, software, or any other type of digital information.

Every document you write, photo you take, and song you download is a file. Files are stored on your hard drive, SSD, or in the cloud as sequences of binary data (0s and 1s) organized in specific formats.

Files and the File System

A file is an abstraction the operating system presents over raw storage. The file system tracks each file's name, location, size and permissions, and maps the logical byte stream onto physical blocks scattered across a disk or SSD.^[2] This is why a file can appear contiguous to a program even when its data is fragmented across the medium.^[2]

Format and Interpretation

The same sequence of bytes means nothing without a format that specifies how to interpret it.^[1] Many files begin with a magic number, a signature in the first bytes, that lets software identify the type even when the filename extension is missing or wrong, since the extension is merely a naming convention, not part of the data.^[1] This is why renaming a .jpg to .png does not actually convert it: the bytes inside are still JPEG, and a real conversion must re-encode the data into the new format.

Text Files versus Binary Files

Files split broadly into two kinds. Text files store human-readable characters through an encoding like UTF-8, and can be opened in any text editor, source code, CSV, HTML, and configuration files are text. Binary files store data in compact machine formats not meant to be read as text, images, video, executables, and compressed archives are binary, and opening one in a text editor shows gibberish. Knowing which kind a file is explains why some files are editable in Notepad and others are not.

Metadata and Size

The file system also records timestamps and ownership separately from the contents, and reports two sizes: the logical length of the data and the larger space actually allocated, since storage is handed out in fixed-size blocks.^[2] Tiny files can therefore occupy more room on disk than their byte count suggests.^[2]

How Files Are Organized

Files are identified by their name and extension (.jpg, .mp3, .docx). The extension tells the operating system and other software what kind of data the file contains and which program should open it.

File systems (NTFS, HFS+, ext4) organize files into folders and manage how they are stored on physical storage media. The file system keeps track of where each file's data is located on the storage device.

Examples of Digital File

Frequently Asked Questions