SIMD, or Single Instruction, Multiple Data, is a parallel computing method that allows a single instruction to process multiple data points simultaneously. This technique is commonly used in applications like image processing, scientific simulations, and machine learning, where the same operation needs to be applied to large sets of data. By utilizing SIMD, processors can execute the same operation on multiple data elements at once, improving performance and efficiency. Many modern CPUs and GPUs support SIMD instructions, enabling developers to write code that takes advantage of this parallelism for faster computation and better resource utilization.