Operating system
Introduction
An operating system (OS) is a crucial component of any computing device. It is a collection of software that manages computer hardware resources and provides various services for computer programs. The operating system serves as an intermediary between users and the computer hardware, making it possible for users to execute applications effectively and efficiently.
History
The concept of an operating system was first introduced in the early 1950s when computers could execute only one program at a time. These rudimentary systems, known as batch processing systems, were not interactive and had to be manually loaded and unloaded. The evolution of operating systems has been a continuous process over the years, with each generation introducing significant advancements.
Types of Operating Systems
Operating systems can be classified into several types based on their functionality and the type of computer they control.
Single-User, Single Task
As the name implies, this type of operating system is designed to manage the computer so that one user can effectively do one thing at a time. The Palm OS for Palm handheld computers is a good example of a modern single-user, single-task operating system.
Single-User, Multi-Tasking
This is the type of operating system most people use on their desktop and laptop computers today. Microsoft's Windows and Apple's macOS platforms are both examples of operating systems that will let a single user have several programs in operation at the same time.
Multi-User
A multi-user operating system allows many different users to take advantage of the computer's resources simultaneously. The operating system must make sure that the requirements of the various users are balanced, and that each of the programs they are using has sufficient and separate resources so that a problem with one user doesn't affect the entire community of users. Unix, VMS and mainframe operating systems are examples of multi-user operating systems.
Architecture of Operating Systems
The architecture of an operating system is its basic structure, which can be categorized into two types: Monolithic and Microkernel.
Monolithic Architecture
In monolithic architecture, all the basic system services like process management, memory management, file management, etc., are tightly coupled and run in the system's kernel mode. This architecture is simple and efficient, but it is also complex and hard to manage.
Microkernel Architecture
In microkernel architecture, the kernel is broken down into separate processes, known as servers. Some of the servers run in kernel space and some run in user space. This architecture is more flexible and easy to extend but is less efficient due to the overhead of communication between servers.
Functions of Operating Systems
Operating systems perform a variety of functions, which can be broadly categorized into the following sections:
Process Management
The process management component of an OS handles the creation, deletion, scheduling, and synchronization of processes. It also manages the allocation and deallocation of memory to processes.
Memory Management
The memory management component is responsible for managing the system’s memory, including the allocation (and reallocation) of memory blocks to programs as they run.
File System Management
The file system management component manages files and directories on the disk, and controls access and usage.
Device Management
The device management component is responsible for managing all the hardware peripherals such as the disks, keyboards, printers, displays, etc.
Security and Access Control
The security and access control component is responsible for ensuring that only authorized users can access the system and that they only have access to those resources for which they have permissions.
Conclusion
Operating systems are a fundamental part of any computer system. They manage the hardware and software resources of the system, provide a stable and consistent way for applications to deal with hardware without needing to know all the details of the hardware, and they provide a host of other services such as resource allocation, scheduling, input/output control, and data management.