Cytology study of what

What is Cytology? Cytology is the study of individual cells of the body, as opposed to histology which is the study of whole human tissue itself.

Cytology is important in modern-day medicine as well.
Cytological tests are used to observe human cells to determine the risk of abnormalities and cancer.
The Pap smear test looks at cells as opposed to pieces of tissue and is used to screen women for cervical cancer.