Image Resolution is typically described in Pixels Per Inch (PPI) which refers to the Number of Pixels contained within Each Inch of a Digital Image.
A Higher Resolution/PPI Image contains More Pixels and is a Higher Quality of Image.
A Lower Resolution/PPI Image contains Less Pixels and is a Lower Quality of Image.
To Calculate PPI:
Multiply PPI × PPI (Pixels Per Inch) to get Pixels Per Inch.
Substitute 1 cm for 1 Inch to find Pixels Per Centimeter or PPcm2.