Operating Systems

Operating Systems

1. CPU

   • Modern processors can execute 4 billion instructions every second
     • More than primary and secondary storage can keep up with
       • While the processor waits for components to catch up it is doing nothing
         • Operating Systems make use of this time by allocating the time to different processes. Each program can run as if it is the only program on the system which allows multitasking
           • Multitasking
             • Multitasking is where a processor appears to be executing multiple instructions at once
             • In reality, it is running commands from each separate task, filling in the time whilst waiting for components

2. GUI and CLI

   • GUI- graphical representation of the computer's functions are shown and several programs can be shown at once
     • Easier to learn and perform
     • More complex so more likely to have errors
     • Takes up more system storage
   • CLI- text based interface where the user types command and the result is shown as text
     • Almost no errors and less system resoiurces
     • Less information is available to be shown