OK it sounds similar but these are two very different places! Previously I mentioned most antique maps were originally bound into books and atlases. A centerfold down the middle made this possible and the map was folded ready to be inserted and bound.
So when you look at a map as in the example here the front of the map is often referred to as the 'recto' from the latin (Leaf), the front side of a leaf. The reverse or back of the page is known as the 'verso'. Thats it in map trade talk 'recto' the front side of the sheet with the image on it and the back is called the 'verso'. Often the verso will have text printed on it but this is not always the case.
For the map to have been bound previously into an atlas it would need whats known as a binders guard or stub. This was simply a strip of paper glued to the back centerfold which enabled the binder to attach the map into the atlas or book. A simple stitching made this possible without damaging or leaving holes in the centerfold of the map.
How to Identify: When it comes to the question is it original or reproduction all the points discussed to date can help you evaluate the antique map you're considering. As mentioned you want to look at whats on the paper, but even more importantly the paper itself. What does the paper it tell you? Is it laid paper or wove? This will help clarify does the paper fit with the claimed age of the map. What is the back of the map telling you? If possible, especially as a novice you want to try and get to see the maps 'in the flesh' as it were. There's nothing like seeing, touching and feeling these antique items. Once you're more confident you can consider distance buying online. But thats a story for another day.