What is a cgi-bin and what do I do with it?
At one time a lot of servers were configured so that all executable program had to reside in one directory. The cgi-bin was the only directory that could contain executable scripts.
Modern standards are different. PHP, CGI and other executables can be run from all directories in the public html folders on most servers. The cgi-bin is still used by some server installed scripts so you should not delete it.