General computing term. SIMD stands for "Single Instruction Multiple Data".
Wikipedia: "SIMD… describes computers with multiple processing elements that perform the same operation on multiple data points simultaneously. Thus, such machines exploit data level parallelism, but not concurrency: there are simultaneous (parallel) computations, but only a single process (instruction) at a given moment… In other words, if the SIMD system works by loading up eight data points at once, the
addoperation being applied to the data will happen to all eight values at the same time.
See also: ParallelFor jobs.