I am not able to understand the following statement from the file limits.h. What is the use of this statement and what does it accomplishes?
/* If we are not using GNU CC we have to define all the symbols ourself.
Otherwise use gcc's definitions (see below). */
#if !defined __GNUC__ || __GNUC__ < 2
It checks if your program is compiled by some other compiler than GCC, or some very old GCC version.