Classification of Operating System (OS) – A Complete Overview

Operating System (OS) is a system software which works as the backbone of a computer system. Therefore, the OS serves as an interface between the computer and its user, allowing proper communication and execution of tasks. Be it running programs, accessing files or even operating hardware, the OS is there making sure that all the components work properly.

In this blog, we will explore the broad functions and categories of operating systems beginning from simple batch systems to the more sophisticated real-time and mobile systems. By the end of this article, you will be able to understand how the various operating systems work and what they are designed for.

What is an Operating System?

An OS is software that runs on your computer and controls or manages its resources which include hardware and software. It is most helpful as an intermediary between the user of the computer and the actual hardware of the computer so that users don’t need to understand how the machine functions to perform tasks. The operating system performs essential functions that are managing CPU, memory, storage and input/output devices.

The OS performs memory management, manages files, and contemplates security, as well as other activities. It also defines how information is stored and retrieved, what rights will be delegated to the users, and how multiple applications in computer devices can function simultaneously without interference. The OS, being the core of the computer, allows a user to perform all mobile and computer tasks from the most basic to a challenging one such as network connections.

Here, we have covered a few functions of the operating system.

• Process Management: The OS chooses which processes to carry out within the available time. The CPU time-sharing is optimised by controlling, scheduling and ensuring a process assignment is well executed.
• Memory Management: Memory spaces are allocated and de-allocated in response to the program according to the requirements.
• File System Management: File management support comprises file creation and deletion, file communication over storage systems, and file architecture.
• Security and Access Control: Security is ensured through users being granted certain levels of permissions through the OS and protected resources or functions from not being accessed by allowed users only.
• User Interface: A user interface is included in the OS, which might be a command line interface or a graphical user interface, allowing the users of the system to operate.
• Error Detection and Handling: This functional unit diagnoses the occurrences of errors within the system and tries to correct them to prevent the system from collapsing.

Types of Operating System

Operating systems have various types, each designed to handle specific tasks and environments. Below are descriptions of the different types of operating systems along with their advantages, disadvantages, and examples.

Batch Operating System

A Batch Operating System processes batches of jobs without manual intervention. It collects jobs and processes them in groups, making it efficient for tasks that need repetitive processing. However, it lacks real-time interaction, meaning users cannot modify tasks once submitted. This leads to longer turnaround times if a job causes delays.

Advantages:

• Efficient for repetitive tasks: It handles large volumes of repetitive jobs efficiently.
• Minimal user interaction: Once jobs are submitted, no user intervention is required.
• Optimised resource usage: System resources are used efficiently as tasks are batched together.

Disadvantages:

• No real-time processing: Users cannot interact with the jobs while they are being processed.
• High turnaround time: Processing a batch can take a long time, especially if a job is stuck.
• Difficult to debug: Errors can only be found after the entire batch is processed.

Examples:

• IBM mainframes
• Unix batch processing systems

Multi-Programming System

Multi-programming is capable of executing two or more programs at the same time by the division of system resources like the CPU and the memory. The OS switches between programs to maximise CPU utilisation, ensuring that it is never idle. This enables efficiency in the use of resources but leads to problems like excess memory use. This type of multiprogramming system is common in areas where there is a need to optimise the system resources such as in the case of a server.

Advantages:

• Maximises CPU utilisation: Such a technique guarantees that the CPU will not be idle for any given time.
• Improves resource efficiency: Resource utilisation is optimised with the running of more than one program.
• Improved user satisfaction: Switching between applications is easy and users do not have to wait for a long time before opening another program.

Disadvantages:

• Potential for memory overflow: Running multiple programs simultaneously can lead to memory management issues.
• Complex resource management: Requires careful management of resources to avoid conflicts.
• Increased system complexity: More complex to design and maintain compared to single-program systems.
• Higher risk of system crashes: If resources are not managed well, it can lead to system instability.

Examples:

• Unix
• Windows OS
• macOS

Multi-Processing System

A Multi-Processing System uses two or more CPUs to perform tasks simultaneously.  A multi-processing system is highly efficient and reliable. Such systems are often integrated into supercomputers and high-end servers.

Advantages:

• Parallel performing capabilities: Tasks are accomplished in a short span of time with many CPUs being used to do the work in a coordinated manner.
• Dependable: If one CPU breaks down the functions can be taken over by other CPUs and hence services can be maintained.
• Expandable: Performance can be enhanced through the addition of other CPUs.

Disadvantages:

• Increased complexity: Managing multiple CPUs adds to the system’s complexity.
• Higher cost: The cost of multiple CPUs and the required infrastructure is significant.
• Synchronisation issues: Ensuring that all CPUs work together without conflict can be challenging.

Examples:

• IBM Blue Gene supercomputer
• Linux-based server clusters

Time-Sharing Operating System

A Time-Sharing Operating System permits several users to work concurrently on a computer system by sharing ’time slices’ of the CPU. Users have to wait a little for his/her turn to take full advantage of the facilities of that system but within that short time, they feel they are the only one using the system. This kind of OS is used in areas where several people want to do the work at the same time.

Advantages:

• Better allocation of resources: Maximises the use of CPU by distributing time among users.
• Minimal latency: The users do not wait for a long time as the system quickly switches between tasks.

Disadvantages:

• Potential for system overload: If too many users are connected, the system can become overloaded.
• Complex scheduling: The OS must carefully manage time slices to ensure smooth operation.
• Security risks: Multiple users accessing the system simultaneously can lead to security concerns.

Examples:

• Unix
• IBM VM/CMS

Distributed Operating System

The Distributed Operating System integrates a number of independent computers and presents them to the users as one. This kind of OS utilises the strengths of different computers to set out one goal and uses resources such as memory, disks, and channels. Typical applications of Distributed systems come in the form of large business and community centres and computer farms.

Advantages:

• Resource sharing: More than one computer can carry out a single operation which means resource utilisation efficiently.
• Scalability: New computers can be integrated within the system to enhance performance.
• Fault tolerance: When one computer is out of service other computers can take over and the work on the same system continues.

Disadvantages:

• Complex setup and management: The main disadvantage of these systems is that they cannot be easily performed because of the confounding nature of the distributed management architecture.
• Network dependency: This system has a major drawback as it completely relies upon any connection with the network, thus if there is a disturbance then it may affect the performing task.
• Security concerns: So much consideration must be put into managing how every computer in the network stores and accesses information to keep it secure from exploitation.

Examples:

• Apache Hadoop
• Google File System

Network Operating System

A Network Operating System (NOS) is designed to manage and support networked computers, allowing them to communicate and share resources like files, printers, and internet connections. NOS provides tools for network administration, security, and data management, making it essential for environments with multiple interconnected systems.

Advantages:

• Centralised management: All the administrators are provided with just one point from where the entire network needs to be managed.
• Resource sharing: It also helps in the easy sharing of network resources such as files and printers.
• Enhanced security: Tools for monitoring and securing networks are present.

Disadvantages:

• High cost: This exposes the organisation to a high budget since utilising and sustaining an NOS is very costly in regard to hardware and software used.
• Complex configuration: This figure depicts a comprehensive configuration process for a network operating system initiation.
• Single point of failure: It means, if the central server goes down, then the complete network is bound to be affected.

Examples:

• Microsoft Windows Server

Real-Time Operating System

A real-time operating system (RTOS) processes the data and decides how to react or what further input to seek, all within a defined period. In many applications such as industrial control systems, medical devices, and automotive systems, timing is critical and RTOS is the best operating system that meets these requirements. RTOS provides a guarantee that no task will be completed later than the precise time that is necessary to meet task requirements.

Advantages:

• High reliability: Ideal for mission-critical applications where failures are not acceptable.
• Efficient resource management: This focuses on the optimal utilisation of resources in line with real-time requirements.

Disadvantages:

• Limited multitasking: Often optimised for specific tasks, making general-purpose multitasking less efficient.
• Complex development: Writing and testing software for an RTOS can be more challenging.
• High cost: Typically more expensive due to specialised hardware and software requirements.

Examples:

• VxWorks
• FreeRTOS

Mobile Operating System

A Mobile Operating System is one that has been developed for mobile devices such as mobile phones and tablets. These operating systems are touch-friendly, power efficient, and have software elements geared towards mobile devices, hence the convenience of the smaller handheld devices.

Advantages:

• User-friendly interface: Optimised usage with the use of touch screen and motion.
• Optimised for mobile hardware: Power and resource consumption are well managed and properly utilised in order to conserve the available battery.
• Wide range of apps: Exploits the broad range of mobile applications available in the market.

Disadvantages:

• Dependence on app stores: Users are often limited to apps available in official app stores.

Examples:

• Android
• iOS

Embedded Operating System

An Embedded Operating System is designed to run on embedded systems, which are specialised computing devices built into larger systems, like home appliances, automotive controls, or industrial machines. These types of operating systems operate in a very minimalistic manner which is achieved in terms of stability and resource usage.

Advantages:

• Highly efficient: Often designed for specific tasks, making them less versatile than general-purpose OS.
• Customizable: It is possible to modify it to fit the usage of the embedded device.

Disadvantages:

• Limited functionality: Usually targeted for a certain purpose which makes them less flexible than an all-purpose OS.
• Problematic to update: Updating or even upgrading an embedded OS can be rather painful.
• Hardware bondage: Highly tied to the hardware, which can make replacements and upgrades challenging.

Examples:

• Embedded Linux
• Windows Embedded

Final Thoughts

The knowledge of the various classifications of operating systems will assist an individual in making the right decision on the one that suits a given purpose. Each type, whether it’s a real-time system, mobile OS, or an embedded OS, has its unique strengths and applications. By knowing their advantages and disadvantages, you can make informed decisions about which system best suits your environment.

An operating system is the central foundation for every computing device, ranging from the supercomputers that have numerous processes to the microcontrollers that have single applications within them. Operating systems are always updated on current changes as new technologies come in. For instance, If you are a developer or simply, a technology geek, it is important to understand how technology shapes the world through realising the types of OS.