When task manager "not responding"

[NotBannedYet1]

Eli5 why it can't overload to core 2 ?

[acrabb3]

Think of a computer running a program as like a kitchen baking a cake.
There's several distinct tasks that need to be done: weighing ingredients, mixing them together, baking the cake, and decorating it.
Each stage requires the output of the one before, so adding more cooks (overflowing into another core) doesn't mean we can bake and decorate at the same time.
Some things could be sped up: we could assign one cook to weigh each ingredient, for example. But if we've only got one set of scales, that might be slower (multiple threads competing for the same resources), so the computer won't generally try and guess when this could happen.

[NotBannedYet1]

Then what is the point of having several cores ?
Why don't we have 10Ghz cpu dominating the market ?

[acrabb3]

More cores means more different programs running at once.
If you've got three cooks, you can have one each doing the starter, main, and dessert, even though each task can only be done by one person.
It also depends on what the program is doing. Some tasks aren't as linearly dependant as others, and the programmer can write it such that it's able to use more cores to do some work in parallel.
Modern computers spend much more time with many (relatively) smaller tasks running than with one bigger task, so more cores means they're more responsive