Stem cells are partially differentiated cells in multicellular organisms that can change into various types of cells and increase indefinitely to produce more of the same stem cell which is considered as the earliest type of cell in a cell lineage. Treatment with those cells is regarded as an innovative approach in regenerative medicine, offering promising capabilities for healing and restoring damaged tissues and organs. Mesenchymal stem cells, derived from different sources like bone marrow, fat, and dental pulp, are highlighted for their self-renewal, immune-modulation, and regenerative abilities. Regenerative medicine is one of the more recent fields or methodologies that revolutionizes the path for upgrading human health and quality of life, relying on the use of stem cells. The process of using stem cells indicates marvelous capabilities for healing and restoring damaged tissues and organs. The current overview examines the science or biology of stem cells, showing their various sources, and their potential applications across a wide range of medical fields, carried by discussing multiple studies exploring the stem cells. The review further explores the potential of stem cell therapy for treating neurological disorders, autoimmune diseases, cardiovascular conditions, liver diseases, ophthalmic conditions, bone injuries, kidney disorders, and dental issues.