Ok I just started playing New Vegas and I was wondering...

-What is the "maintain" option in the inventory (it replaces "repair" in some cases) and what does it do ?
-How come the weapon and apparel's HP bars are "segmented" ?

I know it's a newb question but the wiki doesn't say anything about it...

The segmented bar indicates when the condition of your weapon or armor degrades to the point where you start losing damage points (or damage threshold in the case of armor). To keep these items in top condition, make sure you repair before the condition drops below the segment.

When the bar is above the segment, your option will be to "Maintain." When it goes below the segment, it'll be "Repair." They're basically the same thing, just a difference in magnitude.

Ok, thanks. What kind difference does it make exactly when you maintain ?

Maintain is just that.. Maintaining the condition of your weapon or armor. That's what the segmentation is, the line between repairing and maintaining. By repairing it is to make it to the full potential of the weapon or armor. I for one like this change and hope they stick with it in Fallout's to come