Cell death is a fundamental mechanism of life that is directly associated with organismal growth, development, aging, and diseases and is highly studied life science topic from 1960s to the present day. Cell death can be classified as accidental cell death (ACD) and programmed cell death (PCD). ACD is a form of passive, sudden, and uncontrollable cell death induced by extreme physical, chemical, or mechanical changes in pressure, temperature, and/or osmatic pressure. In contrast to ACD, PCD is an active kind of cell death happening under physiological conditions regulated by genes to maintain hemostasis in healthy as well as pathological cells. There are unique biochemical and molecular processes enabling the pharmacological or genetic intervention of PCD. Advanced research in this field paved the way for the discovery of novel mechanisms in different types of PCD pathways. This chapter summarizes and compares biological and morphological characteristics, molecular mechanisms, and biochemical markers of various PCD pathways including apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis. Additionally, it also tries to explain the involvement of distinct PCD mechanisms in the diagnosis, pathological progression, and treatment of multiple organismal disorders, particularly in malignancies.