Cancer cells emerge from normal cells through genetic and epigenetic changes, disrupting the balance required for healthy tissue function. Unlike normal cells, cancer cells divide uncontrollably, evade apoptosis, prefer glycolysis for energy, and lose adhesion, enabling invasion and metastasis. These differences, driven by mutations, genomic instability, and altered microenvironment interactions, reveal critical insights into disease progression and potential therapeutic targets. Understanding this transformation underscores the delicate equilibrium essential for maintaining life.