Good morning,

Just thought I'd ask here in case someone can help me. I'm not super knowledgable on bikes, and I'm not sure if I can do what I want, or how to do it.

I have a decent mountain bike (or at least I like it ), that I got several years ago, a Wheeler aluminum bike. It has big knobby tires for off road biking. However, I really don't use it for that (and if I had it to do over again, I'd have probably bought a hybrid type bike or road bike). I just got it back out of the garage thinking I'll start using it again. I would like to see if I can put some smoother tires on that will roll better on the pavement/gravel roads around here.
The current tires are 26" x 2.05. But I'm not sure if I have to find that exact same size tire to fit, or if there are other sizes that will go on. What is important, just the 26", or both numbers. Or, if I want smoother tires, which might only be found narrower in size, can I actually just replace the rubber, or will I have to buy all new rims too. I did a quick search to see if I could find the info, but so far haven't stumbled across a site that tells me this sort of information. Or, can I even do that with a mountain bike.

See, I'm clueless, and thought I'd at least try here while I search the internet for the info, just in case someone can quicken my search.

Thanks.