Slots = Threads
If this box is checked, it tells Qube and the application (eg, Maya) to use the specific number of threads listed in the "Specific Thread Count" field. if this is not checked, then the "Specific Thread Count" value is passed only to the application. In most cases, you will want to check this box, unless you have Designer licenses.
Specific Thread Count
The number of threads to use on each instance of the job. The default is one instance per core, which for any moderately sized job will swamp most machines. A better value is 8 (assuming you have 8 cores, as most modern machines do) which means that each instance of the job will take 8 cores. Designer licenses are restricted to 1 slot, so... something bad will happen.
