Operating system

A computer needs a boss.

This boss is a special program. It manages all the parts of the computer. It helps you play games or watch videos.

The boss gives each task its own space. This keeps one program from taking over. It also keeps programs safe from each other. You can find this boss on many things. It is in phones and game machines. Some bosses work on big computers too.

It makes sure everything works well for you.

A computer needs a boss to run. This boss is called an operating system.

It is a special kind of software. It manages the hardware and the programs. The most important part is the kernel. The kernel is the part that always runs.

It acts as a middleman. It helps programs talk to the computer parts.

One big job is sharing resources. A resource is a part of the computer. This includes the CPU, which is the brain. It also includes memory, which is the storage space. The operating system gives each program a share. This stops one program from taking everything. It also keeps programs safe from each other.

You can find these systems on many devices. Android is the most popular for phones. It has a 38% market share. Microsoft Windows is also very common. It has a 33% market share.

Some systems are for big servers. Others are for small things like smart cards. Even your game console has an operating system!

An operating system is a special kind of software that manages a computer.

It acts as a boss for the hardware and the programs. This software manages resources like the CPU and memory. The most important part is called the kernel. The kernel is the part that stays running all the time.

It sits between your apps and the computer hardware. This helps programmers because they do not have to learn every hardware detail. The system also provides common services for things like disks and networks.

One main job is to share resources fairly. Most people want to run many apps at once. The operating system decides when each app gets time on the CPU. It also gives each app its own space in the memory. This stops one program from taking all the power for itself.

It also keeps apps separate so they do not crash each other. Sometimes it uses virtual memory to trick an app. This makes a program think it has much more memory than the computer actually has.

Operating systems have a long history. In the 1940s and 1950s, people used punch cards to program computers. There were no operating systems back then. Later, mainframes used simple systems like FMS or IBSYS. In the 1960s, IBM made OS/360. This was a famous system that allowed multiprogramming. This meant a computer could work on more than one job at a time.

This was a big step for how computers work.

There are many different systems used today. Android is the most popular for mobile devices with a 38% market share. Microsoft Windows has a 33% market share. iOS and iPadOS follow at 15%. macOS has 4% and Linux has 1%.

Different systems are made for different jobs. Some are for big servers or supercomputers. Others are embedded in household appliances. Some are even tiny enough for smart cards.

You can see how much these systems have changed. Early computers used a text-only command-line interface. This looked like a screen with only typed words. Later, Apple made the Macintosh. It was the first popular computer to use a graphical user interface, or GUI.

A GUI uses pictures and icons to make things easier. This success led Microsoft to add Windows to its systems. Today, we use these friendly interfaces on almost every device we own.

An operating system, or OS, is the essential system software that manages a computer's hardware and software resources. It acts as a vital intermediary between user applications and the physical computer hardware. Without an OS, a programmer would have to write code for every specific piece of hardware used by a machine. Instead, the OS provides common services and an interface that abstracts these complex hardware details. This allows applications to run on different hardware without needing to be rewritten.

At the heart of every operating system is the kernel. The kernel is the software that is always running. Other programs on a computer are divided into two categories: system programs and applications. System programs are associated with the OS but might not be part of the kernel itself. Applications are all other software that users interact with directly. The OS manages these by allocating resources like the central processing unit (CPU) and memory.

Resource allocation is a primary mechanism for how an OS functions. On modern personal computers, users often run several applications at the same time. To prevent one program from monopolizing all the hardware, the OS gives each application a specific share of time on the CPU or space in the memory. It also uses virtualization to mask limited resources. For example, virtual memory can give a program the illusion of having nearly unlimited memory. This is achieved by using memory that exceeds the computer's actual physical capacity.

Operating systems come in many different types designed for specific tasks. Multicomputer operating systems manage machines where multiple CPUs share memory. In contrast, a distributed system consists of a group of distinct, networked computers that may be located anywhere in the world. Some systems are "embedded," meaning they are built into household appliances or Internet of Things objects. These embedded systems often do not load user-installed software, allowing for simpler designs. Some are even small enough to run on smart cards using less than 10 kilobytes of space.

Another specialized type is the real-time operating system. These systems guarantee that they will process data or events at a specific moment in time. "Hard" real-time systems require exact timing and are used in military or aviation settings. "Soft" real-time systems can tolerate occasional missed events, which is common in smartphone multimedia. There are also hypervisors, which are operating systems that run a virtual machine. A virtual machine is an application that emulates hardware, allowing researchers to test different operating systems easily.

The history of the operating system shows a massive evolution in computing. In the 1940s and 1950s, computers were programmed directly using plugboards or punch cards. There were no operating systems during this era. In the 1960s, IBM introduced OS/360, which was the first popular system to support multiprogramming. This allowed a computer to work on another job if one was waiting for input/output operations.

Later, the UNIX operating system emerged from the MULTICS project. UNIX became the foundation for many other systems, including the educational MINIX, which inspired the creation of Linux.

As personal computers became common around 1980, the interface of the OS changed significantly. Early systems used a command-line interface, where users typed text commands.

This changed with the Apple Macintosh, which was the first popular computer to use a graphical user interface (GUI). A GUI uses icons and pictures to make the computer more user-friendly. This success led Microsoft to create Windows, which eventually became a stand-alone operating system. Today, these interfaces are standard on almost all consumer devices.

Modern market shares show how diverse the OS landscape has become. Android is currently the most popular operating system with a 38% market share. Microsoft Windows follows with 33%, and iOS and iPadOS hold 15%. macOS has a 4% share, while Linux holds 1%. While Windows is common on desktops, Linux dominates the server and supercomputing sectors. This variety ensures that whether a device is a tiny smart card or a massive supercomputer, there is a specialized system to manage it.