If you've ever tried to install a CGI script you'll have seen the terms CHMOD and File Permissions. Find out what these are and why it's necessary for scripts to run.
Chmod stands for Change Mode and is a command usually needed for installing CGI scripts on a UNIX server. Basically it tells the server what the file or folder permissions are, i.e. can the script read the info, or can it write information as well.
Chmod tells the server the access privileges for a file. For example, common file settings are:
777: all can read / write / execute the file.
755: owner can do all, group / others can read / execute.
644: owner can read / write, group / others can read only.
cgi scripts: 755
data files: 666
configuration files not updated by the script: 644
directories: 777
Many FTP programs give you something that looks like this to set chmod permissions.
This may help you try it out first and find out if you really are setting the right permissions.