Definition of Operating System
An operating system is a program or software that can be installed in a computer system via another program known as boot loader in other to control and managed the device's hardware and other application software.
Furthermore, it acts as a platform for connecting the system hardware with other programs that they may serve the purpose being developed for.
Also, it provides a Graphical User Interface that uses icons to represent files and programs through which the system's user can easily access the files and programs as well as serves as intermediary or mediator between the system's user and the computer hardware.
Finally, though the operating system is a program or application, it is worth to note that without this application; other programs or applications cannot be installed or run in the system.
Objectives of Operating System
The main objectives of Operating system are as follows:
- To control application software installed the how user interact with the system.
- Help to execute application software.
- Present an interface that can ease user in navigation round the system
- Help users in solving their problems easily
- Make the use of the computer hardware in an efficient way
Functions of Operating System
The following gare the functions of Operating System to the computer and users.
Helps to manage the system memory efficiently
Operating System plays a very important role when it comes to memory management both primary and secondary memory. It is the operating system that decides the amount of space that can be consumed by the system's programs by checking the allocation and deallocation of space used by each process.
It also monitors all the process for running applications to check if any has been terminated by the user or unexpectedly. If any is found, then it has to free the space for other programs to use.
Managed the system's processor effectively and efficiently:
It is the operating system that decides the order or ways that any process executed will access the system's processor and also determine the amount of space to be allocated to each of the processes.
Device drivers management:
Drivers are very important translation programs that makes it easy for the device to know when external device is connected and also the kind of device as well as the function of the device. It is the operating system manages these drivers.
Control how the device's hardware interact with the user:
Without the operating system, the device is as good as dead. It is through the help of the OS that the device will understand the kind of commands issued by the user.
Ease launching of application software:
It uses icons to represent application software and files in the device for easy access by the device user.
Efficient and effective file management:
The operating system makes it easy for system's user to managed and organized files effectively by allowing the user to create folder or directory as required as well as saving the files to each of the directories created.
Overview of the system's health:
The operating system makes it easy to check the overall performance and health of the system such as checking the fastness of the system in terms of read and write operation from/to of the system's harddisk.
Monitors and managing I/O devices
The operating system monitors the system for input/output devices connected. If any is found, it will then check for commands or input given by the user via this device, store it in the memory, then give instructions to the CPU on how to execute the commands issued as well as display the results using output devices e.g monitor.
Provides security
Operating system has a security functionality that helps to protect the files stored in the device's memory from unauthorized users and malware.
It also hides sensitive information that can crash your device from access.
Efficient and effective time management
When a device is powered on, there are many processes that are activated. And each of these processes would like to use the CPU time therefore making them to compete for available time. This is where the OS comes into action. The Kernel OS will keep a close monitoring on the rate the processes are requesting the CPU time. If it found any two processes that are very important competing for the CPU time, the Kernel OS will therefore slice the time into segments and allocate them equally to the processes therefore preventing any of the processes from using the CPU time all by itself.
Prevention of Deadlock
A deadlock occurs when one process held a resource that is supposed to be used by two or more process to itself. It is the duty of the OS to ensure that available resources are shared equally between all running processes.
Checks Interrupt Handling
Humans most times consider some of their tasks to be very important and called it high priority task. Same way it is even in computer devices.
Interrupt simply refers to a signal raised or generated by a software or hardware in order to get the attention of the CPU and the process of responding to this signal is called interrupt handling.
The duty of the OS during interrupt handling is to compare the priority of the interrupt with the current running process to see the most important one. If the interrupt is more important, it will stop executing the running process and preserve the CPU state then switch to execution of the requested process.