Background: The life of multicellular creatures is safeguarded by the equilibrium between the constant proliferation of their cells and the elimination of unnecessary or damaged cells. One of the key mechanisms in achieving this balance is apoptosis and its precise regulation. Apoptosis is an ordered and orchestrated cell death program that involves complex interactions between several molecules and several different signaling pathways. Along these pathways, defects can occur at any point, leading to tumor initiation, progression, metastasis, or malfunctions that can even contribute to anticancer treatment failure and reduced treatment sensitivity. Therefore, understanding the underlying mechanisms of apoptosis can significantly enhance our knowledge of cancer origins and progression. Methods: For writing this chapter, the keywords that were mainly used include: apoptosis, the morphology of apoptosis, extrinsic and intrinsic pathway of apoptosis, and apoptosis evasion in cancer and tumor metastasis. All the information was collected from publicly available research articles. Results and conclusion: Throughout this chapter, much focus has been placed on the morphological and biochemical changes associated with apoptosis, different pathways of apoptosis, and their particular relevance to cancers that will ultimately provide a conceptual framework reflecting a promising association between cancer genetics with cancer therapy.