At its core, a file is a contiguous set of bytes used to store data. This data is organized in a specific format and can be anything as simple as a text file or as complicated as a program executable. In the end, these byte files are then translated into binary
0 for easier processing by the computer.
Files on most modern file systems are composed of three main parts:
- Header: metadata about the contents of the file (file name, size, type, and so on)
- Data: contents of the file as written by the creator or editor
- End of file (EOF): special character that indicates the end of the file
What this data represents depends on the format specification used, which is typically represented by an extension. For example, a file that has an extension of
.gif most likely conforms to the Graphics Interchange Format specification. There are hundreds, if not thousands, of file extensions out there.