What is Operating System: Definition, Functions and Types

What is an Operating System?

An operating system (OS) is a fundamental software that controls the resources of a computer, both hardware and software and offers services to computer applications. It bridges the user, application software, and computer hardware, allowing them to communicate and cooperate efficiently. The OS is essential in coordinating and managing numerous computer functions, ensuring seamless and effective resource consumption.

History of Operating Systems

Since the invention of computers, operating systems have substantially developed. Programs were directly loaded onto the hardware of early computers because they lacked operating systems. More advanced operating systems, like IBM’s OS/360, which introduced the idea of timesharing and permitted several users to access a computer system concurrently, began to appear in the late 1950s and early 1960s. The Unix operating system, created in the 1970s, gave programmers a versatile and potent environment.

Personal computers became more common during the 1980s, and MS-DOS (Microsoft Disk Operating System) became common. Graphical user interfaces (GUI) gained popularity in the 1990s, and user-friendly user interfaces were added to operating systems like Windows and Mac OS. Today’s OS alternatives cover various computing requirements, from desktops and laptops to servers and mobile devices.

The demands for better resource management and user interaction have pushed operating systems forward. Programs for early computers were instead loaded directly onto the hardware, bypassing the need for an operating system. Advanced operating systems like IBM’s OS/360 appeared in the late 1950s and early 1960s, ushering in new ideas like timesharing. Unix, an operating system created in the 1970s, provided developers with flexibility.

In the 1980s, personal computers and Microsoft’s DOS operating system became widely available. In the 1990s, graphical user interfaces became popular and helped make computers easier to use. These days, operating systems serve a wide range of devices, from personal computers to servers to mobile phones.

Functions of Operating System

When it comes to optimizing performance and keeping users happy, the operating system (OS) is like the conductor of a digital symphony. The CPU, memory, storage devices, and I/O devices, along with critical processes, memory allocation, file systems, and networked environments, all fall under the purview of this orchestration.

Managing Resources Effectively and Efficiently

The primary function of an operating system is resource management, which entails allocating and allocating computer resources to achieve maximum performance. This includes the following four major categories of assets:

Controlling the CPU (Central Processing Unit): Coordinating Processing Capacity

The central processing unit (CPU) acts as the “digital brain,” and the operating system (OS) efficiently divides its processing resources among running programs to promote parallel execution and give the impression of simultaneous processing.

Planning Procedures: To maximize CPU utilization and reduce idle time, the OS uses algorithms to determine the execution order of tasks.

Multitasking allows multiple processes to operate in tandem, sharing the processing power and ensuring that all tasks are completed effectively.

Management of Memory: Integrating Data Storage and Access

The OS manages memory to ensure programs have uninterrupted access to the needed RAM.

Memory Allotment: When a process is started, the operating system allocates a certain amount of memory.

To avoid memory bloat and maximize performance, the operating system frees up allocated memory as processes end.

It optimizes virtual memory to increase RAM’s useful capacity, allowing continuous operation.

Data Storage Device Administration: Scheduling and Locating Files

Storage device management ensures stored information’s security, availability, and speed. The operating system plays a pivotal role in storage management by:

The OS is responsible for the safekeeping, accessibility, and organization of files on all available drives, including solid-state and hard-disc drives.

Data integrity refers to the absence of tampering with data and the assurance of safe data storage.

The OS enforces consistent file naming conventions and folder hierarchies to keep your data neat and tidy, making it a breeze to find what you need.

Administration of Input/Output (I/O) Units: Helping People Talk to Each Other

There must be clear lines of communication between I/O hardware and software. The OS allows for this interaction, guaranteeing precise data transfer and prompt transmission:

Input/Output (I/O) device communication is facilitated by the OS, which controls peripherals such as keyboards, mice, printers, and screens.

Device-generated interrupts are handled efficiently, with timely responses and no system disruptions.

Management of System Operations: Integrating Fundamental Activities

The OS’s strengths lie not only in its ability to manage resources but also in its coordination of other crucial system operations.

Managing processes is essential to computing because it allows for individual tasks’ beginning, pausing, continuing, and ending.

Memory Management: The OS makes sure memory is used efficiently by allocating and freeing it for process use.

Management of the file system allows for more effective data administration by sustaining file structures, guaranteeing access control, and protecting data integrity.

NOS, or network operating system, facilitates cooperation between machines in a networked environment by allowing for efficient data transfer and sharing of system resources.

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Features of Operating Systems

User Interface: Users use the user interface (UI) to communicate with the operating system. It can have a graphical (Graphical User Interface, or GUI) or text-based (Command Line Interface, or CLI) interface. 

File Management: Users can create, delete, rename, organize, and search for files and folders on the computer using file management. The OS keeps a hierarchical structure for easy browsing and ensures that files are saved effectively on the storage media.

Device Drivers: Device drivers allow the operating system to connect with hardware devices. They are software components. A certain device driver is necessary for each piece of hardware to operate properly. 

Security: A crucial component of contemporary operating systems is security. The OS uses several security measures to safeguard data and thwart unauthorized access. 

Networking Support: Operating systems come with built-in networking capabilities due to the rising prominence of networked situations. This enables PCs to connect to LANs, WANs, and the internet, enabling data transfer and inter-device communication.

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Components of the Operating System

Kernel: The foundation of the operating system is the kernel. It engages with the hardware directly and offers the rest of the OS and apps necessary functions. The kernel is in charge of controlling file systems, devices, processes, and memory.

Functions of Kernel:

  • Process management: To ensure effective CPU use and equitable processing time distribution across tasks, the kernel creates, suspends, resumes, and terminates processes.
  • Memory management: By allocating and releasing memory to processes, the kernel ensures each process has access to the necessary memory space without interfering with other processes. To maximize memory utilization, it also manages virtual memory and page swapping.
  • Device management: The kernel communicates with hardware through device drivers to guarantee proper data transmission and reception. It manages communication with hardware like network cards, keyboards, mice, and printers.
  • File system management: The kernel organizes, stores, and retrieves files from storage devices. It controls directory setups, file information, and file access rights.

Types of Kernels:

The Linux kernel is an example of a monolithic kernel because it provides optimal performance by encapsulating all kernel services in a single binary. This layout makes it easy to get to the functions you need quickly and with little effort. For instance, the Linux kernel enables broad hardware support and sees extensive deployment in server settings.

Microkernel: Microkernels, such as the HURD microkernel, partition the kernel’s primary tasks from the supplementary services provided by processes run at the user level. This layout improves adaptability and modularity, making adding or altering features simpler. Consider the HURD microkernel as an example of how this architecture encourages extensibility while retaining stability.

The MIT Exokernel is an example of an exokernel, which expands on the idea of microkernels. They make hardware resources available directly to applications, empowering software to handle matters of hardware and resources on its own. Although the Exokernel method optimizes application management and performance, it requires vigilant administration to safeguard system resources.

Hybrid kernels combine features of both monolithic and microkernels, like Microsoft’s Windows NT kernel. They keep the most important services in kernel mode for maximum efficiency while handing off the less important ones to the user interface. Windows NT is a great example of how this architecture improves stability and scalability by balancing performance and modularity.

The L4 microkernel family is an example of a nanokernel, which further reduces the size and complexity of the kernel. They are bare-bones in design and provide only the most essential features for handling data transfers between processes and accessing hardware. Kernels based on L4 demonstrate how simplification can boost efficiency and safety.

SeL4: SeL4, a formally verified microkernel, is an innovative take on the traditional kernel development process. SeL4 is very safe because its absence of critical bugs can be mathematically proven. It finds widespread use in industries where absolute dependability is required, such as the transportation and healthcare industries.

Example: The Mach Microkernel

The Mach microkernel is a case study in the separation of kernel functions and user-level services. It is widely known for its role in the macOS architecture. The design of modern operating systems can be traced back to Mach’s influence on the creation of HURD and other microkernels.

The Windows NT kernel is a good example of Microsoft’s hybrid kernel design. It can accommodate user-level components while preserving a modular structure for increased reliability and safety. Microsoft’s Windows NT proves it can strike a happy medium between speed and modularity.

QNX Neutrino is a real-time microkernel used in various embedded and mobile applications, including in-car infotainment and medical equipment. The microkernel architecture makes Deterministic real-time performance possible, making it useful in time-sensitive applications.

Types of Operating Systems

Batch OS: Tasks are bundled and carried out in a batch operating system, which does not require human input. In this system, the operating system runs a series of tasks in order after storing them in a job queue. Before the subsequent task begins, each job is completed in its entirety. 

Distributed OS: A distributed operating system (OS) enables resource sharing and effective processing on a network of connected machines. Computers operating on distributed operating systems may collaborate and communicate without any problems, creating a strong network of interconnected systems. 

Multitasking OS: Multiple tasks or processes may run simultaneously on a single machine thanks to a multitasking operating system (MTO). The OS shifts between tasks quickly, providing the impression that they are being executed simultaneously. Users can work on several applications simultaneously when multitasking, boosting productivity.

Network OS: A Network Operating System (NOS) has already been suggested as a customized OS that handles networked environments. NOS allows several computers to interact and share resources through a network, making it easier to share files, use printers, exchange data, and manage users centrally.

Real-Time OS (RTOS): A real-time operating system (RTOS) is created to adhere to exact timing specifications in time-sensitive applications. Tasks must be finished in real-time systems under strict time limitations. RTOS is frequently utilized in fields where prompt and precise responses are essential, including aerospace, automotive, medical devices, and industrial automation.

Mobile OS: A mobile operating system is designed with portable electronics like smartphones and tablets in mind. The mobile operating system provides touch-based user interfaces, improved power management, and features tailored to mobile use cases, such as mobile app stores and location-based services.

32-bit OS vs. 64-bit OS

Below is a table outlining the main differences between a 32-bit and a 64-bit operating system:

Aspect 32-bit OS 64-bit OS
Maximum RAM Support It usually allows for up to 4 GB of RAM. It can accommodate a lot more RAM (greater than 4 GB). Depending on the version, often between 8 GB and hundreds of gigabytes.
Addressable Memory Confined to a 32-bit (232 bytes) memory address region. A bigger (264 bytes) addressable memory area can access more memory locations.
Performance May be less efficient for certain tasks due to limited memory-addressing capabilities. Generally faster and more efficient, especially for memory-intensive applications and large datasets.
Application Support May not run 64-bit applications natively and may require emulation. Can run both 32-bit and 64-bit applications natively.
Driver Availability Some older hardware may have limited 32-bit driver support. Generally, it has wider driver support for modern hardware.
Software Compatibility Generally, it has good compatibility with older. 16-bit and 32-bit software. Some older 16-bit software might not work, but it has better compatibility overall.
Security Potentially less secure due to limitations in memory protection. Improved security features, including hardware-based DEP and ASLR, offer better protection against exploits.
File Size Support Limited to a maximum file size of 4 GB. It can support much larger file sizes, often up to exabytes.
Usage Common on older hardware or low-end devices. Common on modern computers and servers.


Popular Operating Systems

Numerous widely used operating systems support diverse device kinds and use cases:

  • Windows (Microsoft): One of the most popular operating systems for personal computers is Microsoft Windows. It has an intuitive user interface, broad program compatibility, and a variety of apps.
  • macOS (Apple): Macintosh machines only run the macOS operating system from Apple. MacOS is well-liked by tech fans and creative professionals alike for its svelte appearance, dependability, and compatibility with other Apple devices.
  • Linux (Open-source): Based on the Linux kernel, Linux is an open-source operating system. It is well-liked in both personal and business situations since it is highly flexible, secure, and adaptable.
  • Android (Google): Developed by Google, Android is a mobile operating system largely utilized in smartphones and tablets. Thanks to the Google Play Store, it rules the mobile market and has a big app ecosystem.
  • iOS (Apple): The mobile operating system for Apple’s iPhone, iPad, and iPod Touch devices is called iOS. Apple fans love iOS because of its simple design and seamless interaction with its products and services.

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Choosing the Right Operating System

The following considerations must be taken into consideration while selecting an operating system:

  • Hardware Requirements
  • Requirements for security
  • Compatibility with software
  • Purpose
  • Support and Updates
  • Price

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What is a Real-Time Operating System (RTOS)?

In time-critical applications, a Real-Time Operating System (RTOS) is created to adhere to exact timing specifications. Tasks must be finished in a real-time system under strict time limits. RTOS ensures tasks are completed by set deadlines or at predefined times. Applications where timing is vital to require this capability, such as

  • Aerospace and defense: Real-time systems are utilized in military, commercial, and spacecraft applications where accurate timing is necessary for mission success and safety.
  • Automotive: RTOS controls several features in contemporary cars, including airbags, anti-lock brakes, engine control, and entertainment systems.
  • Industrial Automation: RTOS ensures effective coordination of procedures and machinery in manufacturing and process control systems, maximizing output and minimizing downtime.

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The operating system is the foundation of contemporary computing, controlling hardware and software resources and offering a user interface that enables efficient user-device interaction.

It manages crucial tasks like file system management, memory management, resource management, and process management. From home PCs and mobile devices to high-performance servers and real-time applications, several kinds of operating systems are available to meet a wide range of computing requirements.

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How does an operating system allocate resources for computer hardware and software?

By limiting access to them and effectively allocating them to other programs, an operating system manages a computer's hardware and software resources.

How does the operating system manage memory?

Allocating and releasing memory to processes, optimizing memory utilization, and avoiding memory leaks are all aspects of memory management in an operating system.

Does an operating system allow environments with multiple users?

Many contemporary operating systems allow for multi-user scenarios, which let several people log in and use the machine at once.

What elements should be considered when deciding which operating system is ideal for a specific device or application?

When choosing the finest OS, it is important to consider various variables, including hardware compatibility, software requirements, security features, user interface, purpose, maintenance and updates, and pricing.

How has the evolution of operating systems impacted the computer sector?

The growth of operating systems has greatly impacted the computing industry. Advances in OS technology have enabled the development of more powerful and user-friendly computers, which has contributed to the widespread use of computing in various industries and elements of daily life.

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