Desktop DDR3 RAM
DDR3 is a previous generation of desktop memory, superseded by DDR4 and then DDR5. It remains relevant for one purpose: keeping an older machine running.
The platforms that use it are Intel’s LGA 1155, 1150 and 1151 first-generation boards and AMD’s AM3 and AM3+ — broadly, desktops built between roughly 2008 and 2015.
DDR3 and DDR4 are not interchangeable. The notch in the module is in a different position, the voltage differs, and a board takes one or the other. There is no adapter.
One genuine trap: DDR3 and DDR3L. The L modules run at lower voltage. Many DDR3L modules are dual-voltage and work in either, but a plain DDR3 module may not run in a system that requires DDR3L. Check the motherboard’s manual.
Worth being straightforward: on a machine this old, the biggest improvement per pound is usually fitting an SSD rather than adding memory, if it is still on a mechanical hard drive.