Simple definition
DDR4 is a generation of synchronous dynamic RAM used in computers and servers.
Purpose and use
DDR4, Double Data Rate 4, is a memory generation whose use depends on the memory controller and motherboard.
How does it work?
Modules must meet supported requirements for generation, form factor, organization and memory type.
Example and verification
Check machine documentation and population rules before adding or replacing a DIMM.
Points to watch
DDR4 does not by itself mean ECC or RDIMM. Advertised capacity or frequency alone does not establish compatibility.
In short
Memory generation is only one requirement for a compatible module.