A term used to describe memory integrated circuits which can be accessed simultaneously via two independent address and data busses.
Dual ported memory is often used in video display hardware, especially in conjunction with Video Random Access Memory (VRAM). The two ports allow the video display hardware to read memory to display the contents on screen at the same time as the CPU writes data to other areas of the same memory. In single-ported memory these two processes cannot occur simultanteously, the CPU must wait, thus resulting in slower access times. Cycle stealing is one technique used to avoid this in single-ported video memory.