An operating system refers to software or a program that is used as an intermediary between users and computer hardware. It gives a user an environment where the user can execute applications easily and efficiently.
It can be considered as a platform that manages hardware resources. Operating systems control the allocation of resources and services such as memory, devices, processes and information.
Mobile operating systems are widely used now-a-days. These operating systems are specifically designed to run on mobile devices as mobile phones, smartphones, PDAs, tablet computers and other handheld devices.
Some known operating systems are:
Following diagram illustrates main function of operating system.
Functions of Operating System
Operating system not only acts as an intermediary between software and hardware resources, but also works as Resource Manager. It also controls storage operations, handles process management and memory management. Let us understand these functions performed by operating system.
- Resource management: In professional life, a manager’s role is to utilize his resources appropriately to get the work done efficiently and within prescribed timelines. The same way operating system works with software and hardware resources of a computer. The operating system identifies at which time the CPU will perform which operation and memory is used by which software tool or application. We can say based on the user request to software, the operating system will interact with hardware device and reply to user’s request. It plays a major role of managing input and output devices of computer.
- Storage management: Operating system also controls all the storage operations. It means how the data or files will be stored in the computer hard drive. It allows the user to create file, folder and read and write data of files. Thus, all data related operations are taken care of by the operating system.
- Process Management: Operating system plays a major role in allocating processes and prioritizes them for the user to start, stop or execute based on requests.
- Memory Management: Operating system also helps in allocating computer’s memory to the resources. It provides memory to the process and once the process is completed, it de-allocates the memory from the process.
Apart from the functions above, the operating system’s key areas of responsibilities are:
- Software Platform: It provides a software platform on which other software applications run.
- Task Allocation: It ensures that different programs and users running at the same time do not interfere with each other.
- Basic Task Management: It performs basic tasks such as recognizing input from the keyboard, sending output to the display screens and controlling peripheral devices such as printers and scanners.
Types of Operating System
Most commonly used operating systems are:
- Real-time operating system (RTOS): In this type of operating systems, users do not have much control over the functions performed by the RTOS. They are also called embedded systems. RTOS response time to event is quicker than any other operating systems.
- Single user, single task operating system: This type of operating systems deal with a single user running single application at a time. DOS, is an example of single user, single task.
- Single user, multi-task operating system: In this type of operating systems, a single user does multiple operations/tasks at a time. Microsoft Windows is an example of such operating system. In Windows, only one user can log in at a time but that user can do many tasks at a time such as writing document in MS-Word, playing music in Windows Media Player and surfing Internet through Internet web browser.
- Multi user, multi-task operating system: This type of operating systems, more than one user is logged on the system at a time and can perform multiple tasks at the same time. UNIX and Linux are the examples of multi-task operating system.
Operating System Interview Questions
- What is server operating system?
Server operating system is also referred to as Server OS. It is designed to run on servers based on the client/server architecture. This serves the purpose of managing requests of client computers on the network.
Server OS can be managed on the different types of servers such as Web UI Servers; Email Servers, File and Print Sharing Servers, Database Servers and Application Servers.
Some of the populate Server OS are: Windows Server, Mac OS X Server, and variants of Linux such as Red Hat Enterprise Linux (RHEL) and SUSE Linux Enterprise Server.
- What is mobile operating system?
Mobile operating system is also referred to as Mobile OS. It is designed to run on mobile devices such as smart phones, PDAs and tablets.
The mobile operating system is responsible for managing the features available on your device, such as touchpad, keyboards, WAP, synchronization with applications, email, text messaging and more.
The Mobile OS also determines which third-party applications (mobile apps) can be used on your device. These third-party applications use some of the basic features of Mobile OS and behave based on the nature of Mobile OS. In any third-party application, Mobile OS plays an important role for functioning of that app.
- What is network operating system?
Network operating systems is also referred to as NOS. It provides additional features or functions of connecting computers and devices into Local Area Network (LAN). Network related functions are in-built into these operating systems.
Network operating system does not come in its individual form. The “NOS” is reserved for software that enhances basic operating system with network add-on features to it. Novell Netware and Microsoft Windows Server are examples of NOS. UNIX and Mac OS are the operating systems that have built-in NOS.
- What is operating system virtualization?
Operating system virtualization refers to the use of software that allows system hardware to run multiple instances of operating systems concurrently, allowing the user to run different applications on different operating systems on one computer.
Let us take an example:
If your computer has Ubuntu installed with development environment. You are developing one web application on Java platform. In Ubuntu, you have chromium web browser installed. You are testing your application in the same web browser. To check compatibility of the same with Internet Explorer, you need Windows 7 and Internet Explorer (IE) web browser. You can use Windows 7 and IE by installing virtual box in your Ubuntu and access Windows 7 instance in the same.
Thus, operating system virtualization is very useful when you want multiple OS environments for development and testing purposes.
- What is Chromium OS?
Chromium OS is the operating system based on Linux platform and is designed to run on specific hardware. It offers a user interface that is similar to Google Chrome Web browser and its focus on Web experience. Chromium OS is used on open source project development based on Web. It aims to build an interface for the user that is faster, stable and secure than the existing operating system platforms.
- What is Fire OS?
Fire OS is Google’s mobile operating system developed by Amazon. It runs on the devices such as Amazon’s Kindle Fire e-reader device, the Fire Phone smartphone and the Fire TV entertainment set-top box
- What is the difference between Fire OS and Android?
Fire OS is founded or developed out of Android base. There are some differences. Fire OS runs specifically on the Amazon products and not on Google’s. It supports Silk Browser, whereas an Android supports Google Chrome. Fire OS has Amazon Appstore whereas Android has Google Play Appstore.