Apoptosis is a type of programmed cell death that occurs naturally in multicellular organisms. It involves the activation of specific genes within the cell, leading to a controlled and orderly process of cell shrinkage, membrane blebbing, fragmentation, and ultimately, cell death. Apoptosis plays an important role in maintaining tissue homeostasis by eliminating damaged or unwanted cells, as well as regulating cell numbers during development. It is also involved in various diseases such as cancer, autoimmune disorders, and neurodegenerative conditions.