Dbi is some thing control the actual size of your screen , It also can tell the apps and softwares you downloaded from google play or other web stores what is your screen size
What is DBI
it shortcut for "Dots per inch"
Dots per inch (DPI, or dpi) is a measure of spatial printing or video dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm). Many resources, including the Android developer guide, will use the term DPI interchangeably with PPI, however.Monitors do not have dots, but do have pixels; the closely related concept for monitors and images is pixels per inch or PPI.
Old CRT type video displays were almost universally rated in dot pitch, which refers to the spacing between the sub-pixel red, green and blue dots which made up the pixels themselves. Monitor manufacturers used the term "dot trio pitch", the measurement of the distance between the centers of adjacent groups of three dots/rectangles/squares on the CRT screen. Monitors commonly used dot pitches of 0.39, 0.33, 0.32, 0.29, 0.27, 0.25, or 0.22 millimetres [mm] (0.0087 in).
LCD monitors have a trio of sub pixels, which are more easily measured.
