JEDEC is a standards organisation that's been responsible for laying the foundation for RAM clock speeds and timings for decades. In the case of DDR5, the most recent version of double data rate memory for PCs, the default speed is 4800MT/s and that's to ensure full compatibility with all AMD and Intel CPUs. However, Patriot Group is developing a type of DDR5 stick that pushes this to 6400MT/s and higher, even if the CPU itself doesn't normally support that speed.
While the JEDEC standard is DDR5-4800, all of AMD's Ryzen 7000 series of CPUs happily work with DDR5-5200, and Intel's 14th gen Core processors support DDR5-5600. Even then, you'll often be able to use even faster RAM, such as DDR5-6000, with these chips.
