Starting from the bottom – we have the (out)sole and heel … which are pretty obvious and are the bits that hit the ground. They may be leather, rubber, or some combination of the two. Leather breathes better but absorbs moisture. Rubber grips better. At the bottom of this page, you can see a lot of soles ready for use, a sole being polished as its shoe nears completion, and the inside, or “sock” of a shoe. Both the leather that forms the sock and the actual sole (if it’s a leather one) are made from vegetable-tanned leather, which breathes better than chrome-tanned leather and, when thick (as in the sole) forms a hard and durable surface on which you can walk!
Next up is the welt – which is sufficiently important and interesting to have another more detailed bit of this encyclopaedia all to itself. Welted shoes are the most repairable and arguably the “best”, but cemented shoes (again, see another section) have their place. They are generally slimmer and lighter.