Ginger...This one is for you.
We have posted information on recessed lighting. As you have read, recessed is comprised of 2 pieces, the "can" or electrical housing and the "trim" or decorative piece.
There are tons of trims available, so we will concentrate on the most popular.
The Baffle (no idea who names this stuff.)
The Baffle is without question the most popular trim sold. Named for its baffle interior, this trim reduces glare and in white blends well with the ceiling.
The Eyeball is used prinarily for accent and washing of walls. Quick tip: Buy an eyeball that is regressed, which does not protrude outside of the ceiling like in picture 1.
The Multiplier has a shiny interior usually in chrome or gold. This trim multiplies light and can be a nice accent if you have gold, chrome or bronze accents in the room.
These trims are watertight and used in shower and outdoor applications.