Two abbreviation you should know when taking pictures.
PPI – Pixels per inch DPI – Dots per inch
PPI and DPI can be used in reference to printing images on paper, as well as digital cameras..three dots per pixel. The PPI will be determined by the size of the image. Pixels per inch are the measurements of pixel density. Pixel resolution is given as a pair of numbers, such as 640 x 480. The first number is the pixels being displayed horizontally and the second number is pixels being displayed vertically. Higher resolutions produce sharper images. The higher the numbers, the higher the resolution. The above photo has 4320 x 3240 pixels.