Operating Systems

Operating system manages the system software and act as a interface between software and hardware for computer programmes. System software performs some process like process management, file management, maintaining peripherals devices like printers, disk drives and networking hardware and memory handling. Some of the operating system are windows operating system, Z/OS,VMS, operating system , linux operating system, AIX and OS/400 etc.

FEATURES OF OPERATING SYSTEMS
Some of the features of operating systems which are commonly found in all the operating system:
 Device managing
 File handling
 Memory management
 Security handling
 Processor managing
 Job accounting and handling
 Error detecting and handling
 System performance controlling
 Synchronization with other software and users

OBJECTIVES OF OPERATING SYSTEMS
Main objective of operating systems is to control execution of application programs. It act as an interface between applications and hardware. Some of the objectives of operating systems are:
 Convenience: Makes computer more user friendly
 Efficiency: Utilize the resources efficiently
 Ability to develop: It allows the users to work efficiently, test and install the new system function without interfering with service.

TYPES OF OPERATING SYSTEM
Batch Operating System:
In this process operating system collects different programs along with the data together in a batch process. Operating system searches a job and gathers similar sets of jobs, each job sets are further selected to commands and data. It then assigns some specific number to the set of jobs and they are executed in a row based on the scheduling algorithm.

Time sharing Operating System:
This system allows the users to utilize the system at any time. Timesharing or multitasking is the extension of multiprogramming. The time at which processors takes are shared by multiple users at a time.

Distributed Operating System:
Distributed operating system uses multiple processors for the multiple users to serve multiple real time application. The processors communicate with each other through various communication channels .This type of roughly coupled systems or distributed systems. Generally processors in this system vary in size as well as in function.

Network Operating System:
In this network operating system, users are allowed to share file, access multiple computers in the network through local area network (LAN), a private network or other networks. The system runs on the server and provides the capability to manage the data, applications, user groups, security and other networking functions.

Operating system process
A process is fundamentally a program in execution. The execution of a process must advance in a consecutive manner. To place it in terms, we use programs in a text file and when we execute this program, it turns into a process which plays out every one of the task referenced in the program. At the point when a program is stacked into the memory and it turns into a process, and it can be divided in to four process- stack, heap, text and data (GCF, 2019).

Stack
The process Stack contains the information, for example, technique/work parameters, return address and local variables

Heap
In this process memory is allocated during its run time

Text
The value of the program counter is represented and the content of the processor is registered

Data
Data here contains static and global variables

Process of Operating system
The process is executed in the three different stages and it passes through different state. All those five states are occurred in every process of operating system.

Start
Initial state of this process .It is created / started.

Ready
In this state, the process waits to assign a processor allocated to them by the operating system. If in the start or while running gets interrupted, the CPU scheduler assign to other process.

Running
In this state, instruction is being executed once process is assigned by the scheduler.

Waiting
The process enters in to waiting state when different event occur like input/output or waiting for the resources to be available.

Terminate or Exit:
When the operating system exit or terminate the process, it moves in to terminate state and it waits to be removed from the main memory.

Process scheduling:
The process scheduling is the progress of the process manager that handles the expulsion of the running process from the CPU and the determination of another process based on a specific system (Electrical, 2015).

Process scheduling is a basic type of a multiprogramming operating systems. Such operating systems permit more than one process to be stacked into the executable memory at once and the stacked process shares the CPU utilizing time (web design, 2019)
tion.