DDR3 (Double Data Rate 3) is a generation of computer memory (RAM) that offers faster speeds and lower power usage than its predecessor, DDR2, acting as temporary storage for quick CPU access; it became the PC standard around 2007 before being succeeded by DDR4, featuring speeds from 800 to over 2100 MHz and using a 1.5V (or 1.35V for DDR3L) power supply, with distinct physical connectors (240-pin DIMM for desktops, 204-pin SO-DIMM for laptops) making it incompatible with other RAM types.