Processes that do computing etc get a lower priority. Computing processes are longer and don't need the response time. There we are. MPQ is the rough algortihm used by most operating systems today. The scheduler keeps a list of process queues.
Every queue gets a priority assigned.
Lower priorities have a larger number. In other OSs this is just inverted. Different OSs also use an other number of priorities, depending on for which situations or purposes they are designed. Well, processes in queues with a higher priority get less cpu time, so a smaller 'time quantum' than processes in lower priority queues. In this way, interactive processes get less cpu time and computing processes more.