Each processor on the market uses cores to run workload, yours in question has 2. Some like my 956, or the i5 have 4, FX lineup has 6-8 etc.
Core count is important, but each varies, Intel has stronger cores that can do more work per core per "cycle (Will explain next)" AMD makes up for this by using more.
As for GHz that is how fast each core cycles the information it has been given. So each core runs at that speed. Again, they arent all the same as some processors can do more work per cycle, and run at lower GHz but beat higher GHz CPUs.
There is alot involved with this whole system, if you need any clarification I can go into more detail.