That will depend which program you use for checking the core temperature. You will normally see something like "Core 1" "Core2" and so on since your CPU is most likely a multicore.
If they aren't labeled, figure out how many cores you have, then run something CPU intensive like a game, and see if that number of temperatures rise in unison.
For, say, a 4-core CPU, if you see the temperatures go from
[30, 34, 33, 33, 35, 38, 40, 28] to
[35, 46, 47, 45, 47, 42, 55, 30]
Then you could see that those 4 temperatures(2, 3, 4, and 5 for this example) stayed very close together, and they are probably the CPU temps.