is a piece of clothing
for the trunk
of the body
Colloquially, a shirt for women is often called a top, though this term is not completely restricted to women's clothing.
For such clothing, including vests, sweaters, jackets, etc. one can disinguish:
With regard to covering the shoulders and arms:
- with no covering of the shoulders or arms - a tube top (not reaching higher than the armpits, staying in place by elasticity, see e.g )
- with only bands on the shoulders
- covering the shoulders, but without sleeves
- with short sleeves
- with half-long sleeves
- with long sleeves, may further be distinguished by the cuffs:
- no buttons
- buttons - single or multiple
- buttonholes only for use with cufflinks
With regard to level of the lower edge:
- leaving the belly button area bare (much more common for women than for men)
- until the waist
- covering the crotch
- covering part of the legs (essentially this is a dress; however, a piece of clothing is either perceived as a shirt (worn with trousers) or as a dress (worn by women, and by men just in the special case of cross-dressing).
and levels in between.
With regard to opening:
- left and right front side not separable, put on over the head
- vertical opening on the front side, with buttons or zipper.
With regard to the neck
- V-shaped permanent opening on the top of the front side
- with or without polo-neck
- no opening
- vertical opening on the top of the front side, with buttons or zipper
With regard to pockets: how many (if any), where, not closable, or with a button
With or without collar. Furthermore the collar may have buttons at the tips for a "button-down collar".
Some common shirt types:
- polo shirt - a shirt with collar but only a partial vertical opening with buttons
- dress shirt - a shirt with collar and full vertical opening with buttons
- tank top - a sleeveless shirt
- blouse - ladies dress shirt
- nightshirt - for sleeping
- sweatshirt - with or without hood
- rugby shirt - typically a long-sleeved T-shirt
- Hawaiian shirt - a colourful short-sleeve dress shirt
- golf shirt - a polo shirt
- baseball shirt - usually distinguished by a three quarters sleeve
- fishnet shirt, transparent, see e.g. 
- tube top - a shoulderless, sleeveless "tube" that wraps the torso
- halter top - a shoulderless, sleeveless, backless garment, typically for women. It is mechanically analogous to an apron with a string around the back of the neck and across the lower back holding it in place.