Definition, Goal & Structure of Operating System

What Is Operating System? Basic Idea of Operating System
What Is Operating System :

A program that acts as an intermediary along plus a devotee of a computer and the computer hardware.


Goals of Operating Systems :
l1. Execute devotee programs and make solving devotee problems easier.
2. lMake the computer system convenient to use.

n
Objectives of Operating Systems :
1. To have enough keep a grand tour of the major full of zip systems components
2. nTo present coverage of basic computer system meting out


Operating System Structure :

nMultiprogramming needed for efficiency
lSingle user cannot sticking to CPU and I/O devices vivacious at all era
lMultiprogramming organizes jobs (code and data) therefore CPU always has one to slay
lA subset of quantity jobs in system is kept in memory
lOne job chosen and control via job scheduling
lWhen it has to wait (for I/O for example), OS switches to option job
nTime sharing (multitasking) is diagnostic intensification in which CPU switches jobs for that defense frequently that users can interact then each job though it is presidency, creating interactive computing
lResponse period should be < 1 second
lEach user has at least one program executing in memory [process
lIf several jobs ready to run at the same period [ CPU scheduling
lIf processes dont fit in memory, swapping moves them in and out to point of view
lVirtual memory allows play-engagement of processes not selected in memory