The photo well shows every picture that you have. You use tags and/or date settings to limit that view down to just what you want to see right now. I think of tags as "filters" - I just want pictures of dogs, I click the "dogs" tag.
You also have the option of segmenting by import batch or using folder view.
Collections are there to enable you to assemble an ordered sequence of pictures for a particular project.
Thank you, and you are so right. I am totally new to this product, and I'm just trying to decide if I want to use it over the other products I've been using. But I have to get to the point where I understand it enough to evaluate it. I'm going to play around with the tags. I keep wanting to select a group of photos to work with at any one time and then maybe a subset. I did work with collections a little bit, and that was pretty cool. Thanks again for the help!