stderr in C is actually stderr in unix, "file handle" 2 which is an integer 2, and is a "property" of a unix process. C implementations on non-unix platforms d

stderr in C is actually stderr in unix, "file handle" 2 which is an integer 2, and is a "property" of a unix process. C implementations on non-unix platforms do attempt to simulate the "meaning" of file handles, especially 0, 1 and 2, on non-unix systems the term "file descriptor" tends to be used to describe FILE structs which are a software layer on top of file handles—which include buffering to improve efficiency in some circumstances and mask the difference between a character stream and a block device—and FILE descriptors are a property of userspace software