What is the operating system software
The operating system software is a collection of programs that controls and manages the overall operations of a computer system. It manages the computer hardware, controls the execution of the application program, and provides the set of services to the users.
Operating system software interface between the user, application software, and hardware. Examples of operating system software are Windows, macOS, UNIX, DOS, and LINUX, etc.
An application program cannot access input/output devices or execute the program instructions itself. The operating system performs these tasks through the CPU on behalf of the application program. The Operating system provides the platform to the application program where various application programs are executed.
The operating system software is defined as
A special type of system software that controls and coordinates the overall operations of the computer system is known as operating system software.
Importance’s of Operating system software are:
- It controls and manages the overall operation of computer systems.
- The operating system helps to understand the inner function of the computer system very closely.
- The operating system software acts as an interface between the hardware and the user.
- It provides security to user’s jobs and files.
- It creates the environment to use application software.
- It helps in loading and scheduling the user’s program along with necessary compilers.
- It creates and manages virtual memory.
- It helps in controlling program execution and managing the use of main memory.
- It manages both primary and secondary memory, input/output device, an input/output operation.
Types of Operating System Software
The operating system can be categorized into three major groups.
1. Based on User
a. Single User Operating system
The operating system designed for only one user at a time to operate the computer system is known as a single-user operating system. It provides an environment where a single user can carry out his/her work at a time. Some examples of single-user operating systems are Windows -XP, Windows 7, Windows 8, Windows 10, macOS, etc.
b. Multiuser Operating system
The operating system designed for more than one user at a time to operate the computer system is known as a multiuser operating system. This system is must be able to handle the various needs and requests of all of the users effectively. This system divides the total time into a number of times and schedules the task one after another in a given priority. Some examples of multiuser operating systems are UNIX, Window NT, Xenix, etc.
2. Based on Processing Method
a. Batch System
In the Batch operating system, users do not interact with the computer directly. It is also known as deferred processing or off-line processing in which tasks are stored in the form of batches and processed each batch as a requirement.
A batch is a group of similar types of jobs that are stored in secondary storage especially magnetic tape. It is not a complete operating system. It is a traditional way of data processing mechanism, especially used in mainframe computers’ early days of computing.
In this system, jobs (the combination of data and program) are grouped together and processed one after another. So, the next job gets a chance to be executed only after the completion of the current job.
In his type of OS, users need not wait while the job is being processed. So, there is no user interaction. Batch processing operating system carried out from beginning to end without user intervention. It takes a long computation time. For example, weather forecasting, statistical analysis, etc.
b. Time-Sharing System:
In the time-sharing system, the CPU executes multiple jobs by switching among them, but the switches occur so frequently that the users can interact with each program while it’s running.
The user gives instructions to the OS or to a program directly, using an input device such as a keyboard or a mouse, and waits for immediate results on an output device. Accordingly, the response time should be short-typically for less than one second.
c. Real-Time System
Real-Time operating systems are systems that respond to input immediately. The OS was designed substantially for the purpose of monitoring and controlling external activities with timing constraints.
They are used for those tasks, in which the computer must react to a steady flow of new information without interruption. Most general-purpose operating systems like DOS and UNIX are not real-time because they can take a few seconds or even minutes, to react. It is fast and predictable computing.
Application of Real-Time system
- Rocket launching system
- Monitoring and controlling nuclear power station
- Traffic light control
- Weapon control system
- Airlines reservation
d. Network System
A Network Operating System runs on a server and works under the client/server principle provides the server the capability to manage data, users, groups, security, applications, and other networking functions. The primary purpose of the network operating system is to allow shared files, programs, and printer access among multiple computers in a network. Especially a local area network (LAN), a private network, or other computer networks.
e. Multiprocessing System
A multiprocessing system is one in which more than one processor is linked together in a coordinated way. They share the main memory and input/output devices. Their processors can execute different independent programs simultaneously. They can also execute portions of the same programs.
3.Based on User Interface
GUI stands for Graphic User Interface. It provides the facility to represent programs, files, options with graphical images such as the menu, icons, dialog boxes, windows on the screen.
Users can select and activate the options by pointing and clicking with a mouse or keyboard. Users can identify the type of file or command with the help of icons or graphical images. So it is a simple, easy, and user-friendly system. Examples of GUI-based operating systems are Ms-Window 2007, server, vista MacOS, etc.
CUI stands for Character User Interface and it is an earlier form of the operating system where users have to carry out their tasks on the basis of commands. There are tremendous numbers of commands based on the nature of the task.
The user has to input commands on text mode and as a result, the output is displayed in text form. The user cannot view any graphics, pointing, icons, or menus. It is very difficult to operate the computer on a CUI-based operating system. DOS is an example of CUI operating system software.
Why GUI operating system is more popular than CUI operating system?
GUI is more popular than CUI because of the following reasons.
- In a CUI-based operating system, commands are used to operate the computer whereas in a GUI-based operating system graphic icons, menus, dialogue boxes, and pointing devices are used to operate the computer
- In CUI based operating system there are tremendous commands to perform the different tasks and is a hard task to remember all the commands but in GUI, files and programs are represented by graphics symbol so, it is easy to carry out tasks even if a user is unknown about the commands.
- In the CUI operating system, we cannot preview the content but in the GUI operating system, we can preview the content before it gets printed.
- GUI operating system supports multiple programs to execute at a time simultaneously whereas in CUI based operating system single task can be executed at a time.
- The new users can run programs and operate the computer system easily in GUI-based operating but CUI-based operating system users cannot run programs and access files and folders because of the number of commands.
The major functions of the operating system software
a. Memory Management
Memory is the storage location of data and information in the computer system before or after processing data. Operating system process of managing both primary and secondary memory of the computer. It allocates memory for the process while creating the process and freeing it after the processing is over.
b. File Management
The file system is the most important component of computer systems. The operating system is responsible for managing files or folders stored on the hard disks and other storage devices. An operating system helps in the creation or deletion of files or folders for reading and writing, transferring data, or files from one place to another, and managing the files or folders.
c. Input /Output Management:
The operating system is the process of managing input/output devices and their operation. It controls all the operations of input/output and interacts with the peripheral devices.
d. Device Management
A system is a collection of different devices and peripherals to make these devices work operating system is required. The operating system serves as an interpreter for several devices and languages. Most operating systems use device drivers to translate input and output signals into commands to specific hardware devices.
e. Processing Management
The operating system handles the problems of various tasks for processing. It includes creating a process, allocating resources for the process, scheduling executing, and terminating the process after the execution is over.
f. Command Interpreter
The command interpreter takes command from the user then the operating system translates it into meaningful instruction which computers can understand easily. The commands can be both text and graphical commands.
g. Security Management
The operating system plays a vital role to secure the data and program while loaded into the memory. Security is the mechanism for controlling access to programs or data by the authorized user to gain resources. It protects the data, resources, and information from unauthorized users, hackers, and computer viruses.
h. Network Management
We have to work on different computers to share files, folders, and resources or to communicate from one system to another. The file-sharing mechanism, security, and resources management are managed by the operating system. A network operating system is used to manage networking facilities that use protocols to communicate on the network.
i. Backup and Recovery
The operating system provides the facilities to recover lost data. It protects data and information from loss. Generating data and information from the storage device is data recovery. Backup and recovery assure from loss of data and facilitate to gain of a previous recovery point.
j. Virtual Memory
When there are programs larger than the main memory operating system uses the free space from a secondary device to create a workable space in virtual memory. The whole program is divided into pages. Only those pages required at a particular time are stored in the main memory and the remaining pages are stored in secondary memory and loaded immediately when required in the main memory.