Files present a way to store persistent data (that is data that doesn’t go away when a computer is either intentionally, or unintentionally, turned off). Older systems relied on tape, then magnetic disks, and now solid state media.
A file system is used by the OS to manager and track the files on the media.
A file is a named collection of information managed on secondary storage by the file system. Information about the file is stored in a record. This includes things like where the file starts, etc.
Every file consist of data and metadata. Metadata is data about the data, which can give info about when a file was created, what type of file it is, and much more.
The magic number is a short sequence of characters at the start of the file header, which identifies the file type. The type, determines which programs are allowed to access and interpret the file. In DOS and Windows, the file extension serves the same purpose.
A file extension is a weak form of a magic number because it can be arbitrarily changed without actually changing the file type. However, since it’s not hidden, it is easier for the user to see the file type and didn’t take up that meta data space.
Files was originally found on Access 2 Learn
