A stem cell niche is a specialized microenvironment that supports and regulates stem cells. It provides the necessary signals and conditions for stem cells to maintain their ability to self-renew and differentiate into various cell types. This niche is composed of various cells, extracellular matrix components, and signaling molecules that work together to create a supportive environment. In different tissues, such as bone marrow or skin, the stem cell niche plays a crucial role in tissue homeostasis and repair. By controlling the behavior of stem cells, the niche ensures that the right number of cells is produced to replace damaged or lost cells, maintaining overall tissue function.