Which is understanding of classification an important skill

You should be able to understand the importance of classification because it helps make organisation easier in some subjects and you are able to know what different groups are.

Very hard to understand

Calcinosis is the diagnostic term that means an abnormal buildup of calcium on the kneecap (patellar) surface. it is a term uses to describe a group of disorders in which calcium deposits form in the skin. it is also referred to the abnormal deposit of calcium phosphate.