Are Mountain bike and cruising bikes geared different? What I mean is that I have a MT bike and hit the road more than trails or mountains. Why? Theres not many mountains in Alabama. I was just wondering about the MT bike Cruisers are they better suited for road and trail or are thay about the same as a standard MT bike. My MT bike is not very fast I was wondering also about the speed of the Cruiser or Comfort bike.

I'm not sure what you mean about cruising bikes, but touring bikes, cross bikes and hybrids have almost the same gearing as an MTB.

New MTBs have a cog range up to 34T, but most touring, cross and hybrid bikes have a cogs up to 30T or 32T. The chainrings on some MTBs are slight smaller 42-3x-2x, while touring bikes come with a 48-4x-2X. I'm not saying all, but most that I have seen.

Have you considered getting a road bike? If you ride more on road, you would appreciate the performance of a roadbike.. Even the entry level roadbikes are relatively faster than MTBs, on road..

If you ride on the road, and want to go faster, the easiest way is to put some slick or semi-slick road tyres on your MTB wheels. 1.25" -1.5" size is about right.
There is no "right" gearing. You should use gears suitable for your own strength, load, technique, and terrain.
Many beginers pedal too slowly, often in too high a gear. You should be able to ride in an easy-pedalling gear at 80 revs/min.
Once you can pedal well, you can chose gears which are placed centrally around your favorite gear, and have a range which covers your needs.
For general road riding, a 28/38/48 triple with a 12/30 cog at the rear will work for most non-athletes

Thanks for the info. Ill try semi slick tires.