Memory management is a crucial function of a computer's operating system that oversees the allocation and deallocation of memory resources. It ensures that each running program has enough memory to operate efficiently while preventing conflicts between programs. This process involves tracking which parts of memory are in use and which are free, allowing the system to optimize performance and maintain stability. Effective memory management also includes techniques like paging and segmentation, which help break down memory into manageable sections. These techniques allow the operating system to load only the necessary parts of a program into memory, improving speed and efficiency while minimizing wasted resources.