Cell growth refers to the process by which cells, the basic units of life, multiply and increase in number. This can occur through a variety of mechanisms including cell division (mitosis or meiosis), cell differentiation, and cell migration. Cell growth is essential for many biological processes such as development, tissue repair, and regeneration. It also plays an important role in the progression of diseases like cancer where uncontrolled cell growth can lead to tumor formation and metastasis. Understanding how cells grow and divide is crucial for developing treatments and therapies for various medical conditions.