TraditionalOne Piece - The good ole standby we are all familiar with. The tank suit provides coverage from chest to hip (sometimes the entire thigh). It is probably the most sought after piece of poolside garments both for its variety and its familiarity. One pieces come in an endless array of neck and backlines.
Swimdress - This is the traditional tank suit with an added skirt around the middle. It is usually no longer than mid-thigh. Most of them are attached to the suit but some styles are removable. It is very common for conservative women or those wishing to cover their thighs.
The Ini'sTankini - This is the conservative woman's answer to the ever-so-bare bikini. A tankini is basically a one piece swimsuit that has been cut into two pieces. Most plus size tankinis cover the whole abdomen leaving a slight split above the hip. This cut is more convenient to get off and on. It also allows for mix and matching of tops and bottoms.
Skirtini - A slight alteration to the tankini with the addition of a skirt. Like the swimdress it could be attached or removable depending on the design. This style has the same convenience of a tankini with a little added coverage.
Shortini - This is a newer addition to the whole ini-brigade. The advent of boy short cut underwear for women has transferred to swimsuits. This style is also coveted by swimmers.
OtherMastectomy - Women who've suffered the troughs of cancer and breast removal have the option of a mastectomy swimsuit. They are hard to find but one piece and tankini styles are available for women who have had one or more breasts removed. They contain a soft cup bra with pockets to add a prosthesis.
Just a few terms to get you on your way. Shopping for a bathing suit doesn't have to be a choir. Have fun with it!