<unk>  describes the detail an<unk>  holds. The term applies equally to digital<unk> s, film<unk> s, and other types of<unk> s. Higher resolution means more<unk>  detail.<unk>  can be measured in various ways.  Basically, resolution quantifies how close lines can be to each other and still be visibly resolved.  Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch) or to the overall size of a picture (lines per picture height, also known simply as lines, or TV lines).  Furthermore, line pairs are often used instead of lines.  A line pair is a pair of adjacent dark and light lines, while lines counts both dark lines and light lines.  A resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter.  Photographic lens and film resolution are most often quoted in line pairs per millimeter.
Image resolution
Action potential
Angular resolution
Density
Saturation 
Concentration
Dose Profile
Bioavailability