Streaming SIMD Extensions

In computing, Streaming SIMD Extensions (SSE) is a single instruction, multiple data (SIMD) instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in its Pentium III series of central processing units (CPUs) shortly after the appearance of Advanced Micro Devices (AMD's) 3DNow! . SSE contains 70 new instructions (65 unique mnemonics using 70 encodings), most of which work on single precision floating-point data.

Source: Wikipedia — Streaming SIMD Extensions (CC BY-SA 4.0)