# What is the difference between controlling and computational kernels?

I have just dowloaded Mma 11.3 with a trial licence. In the download page you can see:

That I can use 2 controlling kernels and 4 computing kernels.

What is the difference between controlling and computational kernels?

"Computing kernels" is how many subkernels may run when using Parallel... operations, i.e. how many CPU cores you can make use of.