What is the cgi-bin directory used for?
CGI stands for Common Gateway Interface and it allows scripts to directly interface with the server. This directory or folder is commonly used with Perl scripts (.pl), however other scripts can also be used. While this directory isn’t commonly used anymore, it still is occasionally used, especially with Perl software.
In order for scripts to work, you need to CHMOD them to 755 otherwise you will receive Internal Server Errors.
If you’re not using this directory, it can safely be deleted. If you are using this directory, or there are files in there and you’re not sure if they’re being used, you should probably leave the directory.