Image Resolution

Terms like resolution calculation, image dimensions, screen width, etc. are a great mystery to laypersons, because the terms relate to a very technical branch of desktop publishing. The issue is further confused by the fact that all three terms essentially express the same idea. The names simply sprung from different branches of the same field, though some still prefer to distinguish between them.

First of all, the print resolution is given in DPI, which indicates the number of dots (print points) per inch. In addition, the screen resolution is defined in LPI (lines per inch) to indicate the amount of printable screen lines per inch. Last but not least, the unit PPI (pixels per inch) is used to indicate the scanner or monitor resolution.

[...]