All operating systems have file attributes.
Some are incredibly simple, like DOS, with their readonly, system and hidden attributes, while some are incredibly rich, like Novell with its read, write, create, delete, filescan, supervisor, accesscontrol. You can see the file permissions by doing the ls command with the proper arguments. Below is an example. Note the column on the left indicates the permissions for the file for each user population. Without getting into a big UNIX thing, I'd like to show you how to make a CGI script executable to all users.