PC4: In the context of DDR4 memory, "PC4" is an abbreviation for "Partitioned Component 4." It's a module classification that indicates the memory module's data transfer rate, voltage, and other technical specifications. Specifically, "PC4" is associated with DDR4 memory modules.

8GB: This refers to the capacity of the DDR4 memory module. In this case, the module has a total memory capacity of 8 gigabytes. This indicates how much data the memory module can store and quickly access for the computer's operations.