c - What's the difference between a file descriptor and file pointer?

Question

I want to know the difference between a file descriptor and file pointer.

Also, in what scenario would you use one instead of the other?

Answer 1

A file descriptor is a low-level integer "handle" used to identify an opened file (or socket, or whatever) at the kernel level, in Linux and other Unix-like systems.

You pass "naked" file descriptors to actual Unix calls, such as read(), write() and so on.

A FILE pointer is a C standard library-level construct, used to represent a file. The FILE wraps the file descriptor, and adds buffering and other features to make I/O easier.

You pass FILE pointers to standard C functions such as fread() and fwrite().