Non-Uniform Memory Access (NUMA) is a computer memory design used in multiprocessor systems. In a NUMA architecture, each processor has its own local memory, but can also access memory that is local to other processors. This design helps improve performance by reducing the time it takes for a processor to access its own memory compared to accessing memory from another processor. In a NUMA system, memory access times vary depending on the location of the memory relative to the processor. This means that programs must be designed to take advantage of local memory to achieve optimal performance. Operating systems and applications often include features to manage memory allocation efficiently in a NUMA environment.