An operating system is described as an event driven program, what is expected by event driven? Explain how the dispatching operation fits this operation.
Answers: This be once also certain as "interrupt" driven.
The CPU executes a "process" call the "Scheduler" surrounded by a somewhat circular mode (also agreed as "Round-Robin") by listen for or wait for interrupts or events.
Examples of these are:
Key is pressed
Mouse button is clicked
Program desires to write to disk
Program requirements to read from disk
Packet requests to be sent
Packet requests to be received
And several, plentiful others
Each of these deeds is an "event" or "interrupt" to the CPU.
These adjectives impose the CPU to furnish "undivided" attention to the event or interrupt by rectitude of a CPU "time-slice".
Anyway, you procure the thought. The CPU is the big boss who only just sits in attendance waiting to afford audience to anyone who comes knock on the door. If the CPU bestows blessings on the event or interrupt requestor afterwards the Scheduler, or Dispatcher as you phone it, grant access to resouces available on the system to the requestor surrounded by a controlled rage.
Hope this help. Have fun, :)