Computer Operating Systems

In this section, I am going to be teaching you in details operating systems in general.
When learning about hardware and software of a computer system, you came across the meaning of operating system. In that section I said, an operating system (usually called OS for short) is a program that is responsible for controlling the activities of a computer system, its functions and management of different software activities in the computer system.

An operating system can also be defined as a computer software that is responsible for controlling and directing the activities of a computer system. Comparing it to a human being, you can say that operating system is just like the brain of a human being, which directs the rest parts of the body on what to do, how to do it, its performance and activities.

Functions of Computer Operating System

• 1. Device Management - The OS manages all hardware devices of the computer system. It also keeps track of the device various activites such as when an input device is plugged in, or when an output device such as a printer is disconnected from the computer system. The OS manages all input and output devices (Keyboards, Scanners, Microphone, Storage devices etc)
• 2. Input and Output Management - This is also similar to the device management explained above. The OS is responsible for controlling input and output activities as well as data provided by those devices to a computer system.
• 3. Process Management - The OS manages tasks while processing (during execution), this it does by properly allocating resources to tasks in process; enabling them to send and receive information that is useful to them. Process management also involves process scheduling (that is the assigning when and how a process will kick start).
• 4. Memory Management - Memory management is another function of a computer operating system which entails the management of the computer's primary memory. The OS allocates memory to on going tasks, keeps track details of its location, status and other necessary details.
• 5. File Management - This refers to the OS performing file management functions such as reading a file, opening a file, deleting a file, recovering deleted files etc.
• 6. Time Sharing - The OS is also responsible for the allocation of time to users of computer system who is sharing the same resources (printer, scanner etc). Time sharing gives multiple users of a computer system to use computer resources simultaneously (at the same) or one after the another.
• 7. Interrupt Handling - In an operating system (OS) there is an interrupt handler that is responsible for handling any event that needs urgent attention. An interrupt usually terminates or pause the ongoing event of a computer system in other for the users to attend to it with the help of the OS.
• 8. Security - The OS performs this function by providing protection to various computer programs and resources such as the memory, CPU, software programs, disks etc. Security ensures the computer system's integrity, confidentiality and availability by protecting it against malicious programs, malwares or unauthorize access.
• 9. Command Interpreter - One of the functions of an OS is the interpretation of commands that is being entered by the user (humans - You and I). It reads a command, understands it and execute the command efficiently.
• 10. Virtual Storage - The OS makes each running program thinks it has access to all of the storage. Virtual storage makes it possible for the OS to load programs bigger than its physical memory.
• 11. Program Control - The OS is responsible for controlling how a program should be directed in the computer system. It sets standard applications to use, and also all external hardware devices are also controlled by program software.
• 12. Provision of Interface - Operating system provides interface (point of communication) for users to be able to input data, store, retrieve and manipulate files and other kinds of documents.
• 13. Communication Management - Communication management function is also another function of the operating system which can be done in two ways: By sending messages between ongoing tasks and sharing memory and other resources with various users. The seven layers in communication from bottom to top includes: Physical layer, Data link layer, Network layer, Transport layer, Session layer, Presentation layer and Application layer.

Now that you have learnt about the functions of a computer operating systems, lets look at the following operating systems below.

Batch Operating System

A batch operating system is that type of operating system whereby similar jobs to be executed are being grouped into batches and submitted to the computer for processing. In this type of operating system, input jobs are being prepared in an off-line device such as a punch card which will be sent to the computer device for processing. Users do not directly interact with the computer system in a batch operating system. Examples of batch operating systems includes: Payroll System, Bank Statements, etc.

Distributed Operating System

Distributed operating system is a type of operating system whereby distributed applications makes use of multiple central processors, connecting multiple computers through a single channel of communication (LAN or WAN etc). Types of distributed operating system includes:

• 1. Client-Server Systems - This involves the process whereby users (clients) make a request from the server, and the server responds by providing the user with what it wants. In this process, it can serve many users at the same time using different processors. Proper examples of client-server system are the World Wide Web (www), Network Printing, Emails etc.
• 2. Peer-to-Peer Systems - This a type of distributed operating system which allows the sharing of resources between peers without having to depend on a central server. They are usually connected to each other via the internet. Examples of peer-to-peer systems includes: Cloud servers, business messaging applications and content distribution etc.
• 3. Middleware - Middleware is another type of distributed operating system which provides services and capabilities to application program outside of what it is suppose to have. It enables different computers to be able to exchange and make use of information and data in all running applications. Examples of middleware includes: database middleware, server middleware, web middleware etc.
• 4. Three Tier - A three tier distributed operating system is a type that organizes applications into three logical and physical tiers: Presentation tier - Physical Interface, Application tier - Logical Processing point and Data tier - where data related to information are stored, for example a database and its operations. An example of three tier application is an e-commerce website.
• 5. N Tiers - This is a type of distributed operating system that organizes application into three or more logical and physical tiers. It is the type that is distributed among many computers in a distributed network. A an example of n-tiers may include mobile applications.

Time Sharing Operating System

A time-sharing operating system which is also known as multitasking systems is the system by which each task being carried out by different users is given a time of the CPU. Time sharing allows a number of persons located at different points (terminals) to use a particular computer system simultaneously (at the same time).

Network Operating System

A network operating system is can be defined as that computer operating system that is used to connect workstations and personal computers together under a local area network (LAN) or wide area network (WAN). OS makes it possible for communication and resource sharing between its connected workstations, personal computers or terminals. The two major types of network operating system are: Peer-to-peer network operating system which enables users to share network resources that are available in a common location. Client-Server network operating system whereby there is a server that provides users with requested resources.

Real Time Operating System

Real time operating system are those type of operating system that are designed to handle real time applications that processes data as they come in. In real time operating system data processing is done in a fixed and small quantum of time without delay. Real time operating system are very fast and they provide quick response especially for transaction applications that requires quick transaction processes. Examples of real time operating systems includes: Command Control Systems, Airline Traffic Control Systems, Network Multimedia Systems, etc.

Multiprocessing Operating System

A Multiprocessing operating system is that type of operating system in which two or more processors (CPUs) is used in the computer system. The use of multiple processors in a computer system helps to speed up tasks processes and save time spent. Multiprocessing Operating system are very much faster than normal operating system. An example of Multiprocessing OS is UNIX OS.

Mobile Operating System

These are operating systems used in mobile phones, tablets and smart watches that enables them to run applications and other tangible programs. Examples of mobile operating systems includes: Android OS, iOS, Symbian OS, Windows Phone OS, Palm OS etc.

Advantages of Computer Operating System

• 1. User Interface - The computer operating system provides a means by which the user, the computer hardware and software interact.
• 2. Resource Sharing - A computer operating system provides room for users to share the same resources using the same computer system.
• 3. Data Safety - The security of data is also one of the responsibilities of a computer operating system. An OS safe guard's data integrity.
• 4. Multitasking - Computer operating system provides users with the ability to do multiple tasks at the same.
• 5. Hardware and Software control - The computer operating system also controls hardware and software, its input and output devices and other application software.

Disadvantages of Computer Operating System

• 1. Cost - Some operating system and its devices are very costly such as MacOS. They are expensive and not easily affordable by middle class earners.
• 2. Complexity - The languages used to design some operating system are sometimes very complex (that is, they are not easily understandable) which makes users unable to solve some problems that arises.
• 3. Malware Threats - Some of these computer operating system is prone to virus which are gotten from corrupt files or viruses from downloaded applications placed by hackers.
• 4. Fragmentation - Fragmentation is whereby a memory breaks in pieces due to the fact its processes are bigger than that of the memory storage. It can be, whereby the computer storage is unable to handle large tasks and processes.
• 5. Privacy Loss - Some operating system can suffer from privacy due to lack of security and poor data protection and integrity.

Just as human beings or other similar higher animals (Dogs, Cats, Horses, Lion etc) brains are different, so also, we have different types of operating systems.

In the hardware and software section in this computer basics tutorial, you have already seen the different types of operating systems with little knowledge about them. But in the next section, you will be learning them again in details with their features, advantages, disadvantages and the main purpose they meant for, in other for you to make the right choice when choosing which operating system to install in your computer device.