Physician specialists all share the same goal of helping patients become or stay healthy. However, by specializing in one area, they can focus on one specific group of patients or diseases.
Medicine on its own is a very broad field, but physician specialties allow doctors to become experts in one area. This enables them to offer higher-quality care for their patients. Different areas of medicine also require different skills and competencies, so specializing in one area allows physicians to make the most of their abilities.