A pmc identifier is like a name tag for a special kind of computer memory. This memory is called PMC, which stands for "Processor Memory Controller." Think of PMC as a special helper that helps the main computer processor get things done more quickly.
But because PMC memory is different than regular memory, it needs its own special tag or name that the computer can use to find it. That's where the pmc identifier comes in. It's like a special name that the computer can use to talk to PMC memory and ask it to do things.
Just like how you might have a name tag with your name on it at school, the pmc identifier is like a name tag for PMC memory. It helps the computer processor find and use this special memory quickly and efficiently.