The purpose of the stat() system call is to obtain details about a file object you are interested in. Details from the inode are returned (in a structure by the C function).
The details obtained are roughly those you would see using "ls -ld $fname" such as the file type, size, timestamps and so on.
stat() has a related function lstat() that does not follow symbolic links (hence lstat() returns you data on the link rather than what it points to).
The same details are obtained in a list context by the Perl function. http://perldoc.perl.org/functions/stat.html