Check out this link: Types of Orchids
As for your questions:
1st photo is of a Dendrobium orchid. The second photo is of an oncidium type orchid. Both orchids appear very healthy and seem to have good roots. I do not recommend growing in sphagnum, but your orchids seem to be fine. If these are brand new, you might consider repotting into a bark mix that will not retain so much water.