The way permissions are set-up on different wikis can vary, but in general...

Sysops

Moderators, or 'sysops' in general wiki terms, are known more generally as 'administrators'.

Who are the sysops?

You can find out who the sysops are at Special:ListUsers/sysop. In the EVElopedia, they are composed by the YARR team, who is primarily responsible for the EVElopedia content, but also CCP members and other ISD (volunteers) Teams.

What can a sysop do?

There are a number of extra features available to sysops. The key ones are as follows:

Protecting and unprotecting pages, and editing protected pages

'Protecting' a page prevents normal users from editing the page at all. There are several reasons why a particular page might be protected. For more information see Help:Protected pages.

Deleting pages, and undeleting.

A page can be deleted semi-permanently, such that it is no longer available (even in the page histories) for normal users. Normal users do not have this power. See Help:Deleting a page.

Blocking a user or IP address, and unblocking them.

Users can be blocked from the wiki. This is a useful way of keeping out persistent vandals. Users are identified by their registered user name, or by I.P. address, and can be blocked permanently, or just short length of time to give them a "cooling off" period.

See EVElopedia Policies

Patrolling, and seeing patrolled edits.

This is a way of coordinating with other sysops, to ensure that every edit of the wiki has been checked over by a trusted user.