There are several types of 'finishes' for paint products.
These are listed below in order of 'luster' (or shine):
A semi-dry finish with little surface reflection. This finish feels a bit smoother and less dry
to the touch than the flat finish.
A mild sheen with a somewhat smooth surface. This finish still feels a bit textured and just a little dry to the touch.
A moderately reflective finish. A surface coated with this finish will feel smooth. This is an ideal finish for high-traffic areas such as entryways, and for areas that accumulate grease and moisture such and bathrooms and kitchens. This finish is also commonly used on woodwork applications (doors, frames, baseboards, windows, wood trim, etc.).
This is the shiniest of the finishes. A surface with this finish feels almost glassy and a light shined directly onto the surface will form a halo in the shape of the light source. This finish is primarily used in decorative application.