Apoptosis is programmed cell death and is crucial for development and tissue homeostasis. It can be initiated by various stimuli and can progress through a receptor-mediated extrinsic pathway or an intrinsic pathway that starts with mitochondrial events. Both processes involve the activation of caspases. Apoptotic cells undergo distinct changes in cell morphology such as cell rounding, plasma membrane blebbing, and nuclear fragmentation. A spectrum of key players is involved, including transcription factors such as the tumor suppressor p53 and FOXO3a that drive expression of pro-apoptotic genes, effectors such as Caspase 3 and ROCK1, and factors like PARP and AIF that function in a caspase-independent pathway.