There is such an abundance of Orchid types that to list them all in a single piece is not possible.
At the outset the best thing to do is to divide Orchids into two initial family groups.
Oncidium Orchids constitute the largest of the groups. The Orchids belonging to this group happen to be the most familiar with blossoms that are petite with an oversize "lip" at what may be called the 6 o'clock point. The next group comes under the rubric of the Phalaenopsis Orchids. This kind of Orchid is not as diverse as the Oncidium Orchids, they are still very much favored by those who love to grow Orchids as a hobby. The Phalaenopsis Orchids do not have a large "lip" at the 6 o'clock point, but their flowers are considerably larger.
The Phalaenopsis Orchids may not be as large a type as the other of the Orchid types that can be found growing naturally, but since human beings have been cultivating them, there have come to be literally thousands of varieties that have become cross-bred. These Orchids are usually just called Phals for short, but these should not be confused with Paphs (Paphiopedilum Orchids) which happen to be a sub-group among the Phals.
The Oncidium Orchid types are the types that people usually see in various displays in hotels or at most weddings. They do well as potted plants and are remarkably beautiful when they are blooming. They have branches which are referred to a sprays and these have usually a 100 flowers in every spray. If someone puts up more than one plant in some specific display, they become virtually impossible to match as a flower arrangement they are so very impressive.
The Phal Orchid types on the other hand do well as center pieces in flower arrangements that tend to be a lot smaller. The floral industry finds these Phal types the easiest to grow for commercial purposes. The global market for these Orchid types used for corsages or for premade arrangements by florists is huge. The flower sizes can be as large as six inches with color schemes that range from pure white to a deep purple. Thus they are highly favored by creative florists.
Although neither type of Orchid is naturally found in America, hobbyists can still grow them in most of the states in the country. (the only exception comes up with those Oncidiums that you may find naturally growing in the State of Florida.) Since most Orchid types prefer a moist and warm environment, they can be fairly easily cultivated if such an environment is well stimulated. If and when they are rightly taken care of, they can bloom beautifully in the autumn of each and every year.
If you are a person who wishes to cultivate house plants, you can't go wrong with Orchids. If you go through the initial stages of caring for them, they become easy to take care of and do pretty much well on their own.