What does "site-wide" mean?

I'm reading man hier, which says: > /etc > > Contains configuration files which are local to the machine. Some larger software packages, like X11, can have their own subdirectories below /etc. **Site-wide** configuration files may be placed here or in /usr/etc. Nevertheless, programs should always look for these files in /etc and you may have links for these files to /usr/etc. What does "site-wide" mean? Is it synonymous with "system-wide", that is, for all users on the system?