Returns information about the IRC server's DNS cache.
Note, since most clients have a builtin DNS command,
you will most likely need to use /raw DNS to use this.
There are also 2 other variants:
'DNS l' will show you the DNS cache entries
'DNS i' will give you details about the nameserver config
Computers are machines that cause trouble you wouldn't normally have if you wouldn't have a computer.
That is something completely different. Read the monual for what it is.
Normal users should not have access to that command at all, it is an oper command.
Opers will see that information with or without access to the command, becuase it's the cache of IPs that have connected to your server. It also gives the DNS information of the server the IRCd is running on. If you don't want your opers seeing that information, then don't give them oper.