THE operating system is program controls the execution of application programs and
act as interface between applications and the computer hardware.
>> THE operating system as a user/compute interface
1) memory management
>>. memory management refers to primary memory and main memory
. The operating system handles the responsibility of storing any data,
system programs, and user programs in memory.
.when programs is executed, it has to be present in the main memory.
.main memory provides a fast storage the can be accessed directly by the cpu.
> OS does the following activities for memory management
.allocates and deallocates the memory space
.keeps a record of which part of primary memory is used by whom and how much
.de-allocates the memory when a process no longer need it.
> TYPE OF Memory Allocation
1. Fixed size of partition Allocation:
--In this of memory alloction , equal memory is provided to each process.
2. variable size partition allocation:
-- in this type of memory alloction, space in main memory is allocated strictly according to the need of process
2) process management
>>.every software or program that runs on a computer , whether in the background or in the frontend, is a process.
.TO complete any task, any process requires some important resources like CPU time ,memory, file, I/O devices,etc.
. these resource are allocated to any process by operating system
>TYPE OF PROCESSES
1. Operating system process
-Operating system process execute system code.
2.User process
-While user process excute user code
3 ) Deice management
>>. an operating system manages device communication via their repective drivers.
1.keep record of all devices attached to the computer .
2. allocates the device in the efficient way.
decides which device to be allocated to which process and for how time .
3. de_allocates devices when they are not required.
