Random Access Memory (RAM) is where data the CPU is working with is temporarily stored. More RAM is generally better, although there are diminishing returns above 16GB for consumer PC, while 32-bit versions of Windows only support a maximum of 4GB. Speed, measured in MHz, is another consideration, as is latency, but most importantly memory needs to be compatible with your motherboard: it’ll either be DDR, DDR2, DDR3 or DDR4, and modern AMD- and Intel-based PCs use DDR4 memory alone. Smaller SODIMM modules for laptops and mini PCs and ECC registered memory for servers are all available in this category.