Whats the difference between

An Island a Sim and a Regine and which one is US$195 a month and which one is US$295 a month maintenance fees

$195 was a 'grandfathered' fee for the old class 4 regions, $295 is the fee for the newer class 5 regions.

Class 4 owners were given the chance to upgrade to 5's and the higher fee.

Generally. class 5 regions are meant to have better performance than class 4's, although once it's been filled with a couple of dozen campers and a mall or club lagging it to death, most people can't tell the difference.

I believe "soon" is the time Linden Lab gave for looking at land prices again after the last price upping, so I wouldn't be overly surprised if that difference went, or the gap was shrunk, over the next month or so.

or is she asking the difference between a sim and an island?

yes it was 2 questions
Q? 1 what is the difference between An Island a Sim and a Regine
Q? 2 which one is US$195 a month and which one is US$295 a month maintenance fees

A Mainland Sim or a Class 4 (or below) island will cost you $195 a month in maintenance fees.

A class 5 island will cost you $295 a month in maintenance fees.

If you buy an island from LL via the land store you'll be paying $295 a month.

If you win a mainland auction you'll be paying $195 a month. However auction sims initially cost more than islands (most of the time anyway).

Is a Sim, Island and Regine the same thing?

As far as a 65536 sq m land mass goes, generally yes.

The difference tends to be a "region" is usually described as the mainland (mostly Linden landscaped and unzoned) whereas an 'island' is usually a privately run region which may or may not have its own rules.

A sim, an island and a region are basically the same thing: 65536sqm of land, or a square on the map.

*sim* (simulator) refers to the independant software program that runs everything that goes on in that square of 65536sqm (physics, communications, objects, avatars, uploads/downloads, and so on...). There are 4 simulators running on each server.

*region* is the virtual representation of what's going on in the sim. It's the 65536sqm of virtual land.

*island* is the deprecated term for a private region that players can purchase, as opposed to mainland regions. Nowadays private regions are not necessarily always islands surrounded by water, so they tend to prefer the term "private regions" and "private estates" (an estate is one or several private regions that have the same owner).

so basically, each server runs 4 sims. Each sim runs a region. a region can be mainland or private, and is part of an estate.

A private region offers total control over the sim: you can restart it, control parcels, zoning access rights, atmospheric settings, and access much more configuration options, for 295US$. When you own a mainland region, you basically own nothing more than a 65536sqm parcel of land, for 195US$.