DPI - Dots Per Inch
DPI is used to measure the clarity of a picture both in a digital print and in a computer System. The more "Dots Per Inch" a picture has, more clearer it appears. It is one of the criteria to measure the Picture Printing Quality of a Printer or picture viewing quality of a device.
It is the measure of the spatial density of dots in a picture. The more dots per inch, the higher the resolution. It measures how many dots fit into a linear inch. A resolution of 600 dpi means a photograph is printed with 600 dots across and 600 dots down, so there will be 3,60,000 dots per square inch.