Why do we need it?
In: Technology
It’s the manager. It’s the software that manages all of the computers resources to make sure all of the other software that wants to use those resources can do so in an orderly fashion.
There has to be something managing all of the various software a computer runs and how it interacts with the hardware of the computer and that’s the OS.
Without an OS each piece of software would have to manage this individually and that’s a lot of repetitive functionality that everyone would have to include in their software
Programs can run on bare hardware, e.g. the software in an older microwave oven that you can’t talk to across the Internet, but it’s a lot of work. Instead, you can make the software a lot cheaper if you can buy an operating system that does some of the work for you. There are several embedded OS companies, in addition to Apple and Microsoft. It’s simple economics for a microwave company, you spend $2/unit on an OS, or you pay your programmers $2M more to make a program that runs on bare hardware.
A unified interface layer between programs and the physical devices on the computer. Allows developers to program one app which the OS translates into commands that work correctly with the computer’s hardware, and is also usually responsible for maintaining system security and integrity, making sure different concurrent programs don’t interfere with each other, and a few other core features.
The operating system is a computer program that is run immediately on startup of your computer. It controls all other programs that run on a computer. The OS allows your computer to do things like run multiple programs at the same time and read/write files. It also might include drivers that allow playing audio, taking input from a keyboard, and displaying things on the screen. Many popular OSes also include a user interface, like windows and navigation. For mobile operating systems, the equivalent would be the home screen, app management, and swipe controls.
An operating system is a piece of software that acts as an interface between the physical hardware and the applications running on the computer.
Initial computers didn’t have operating systems. You would turn the computer on and would be met with a text box (if you have a windows computer, press Ctrl+shift+enter to see what it would have been like), you could insert a disk containing a application into the computer, and then type out a often complex command to get the computer to run the application.
Then Bill Gates came along and had the idea of a application that ran applications, that would run automatically when it turns on. An OS allows there to be a visual interface for the user, rather than a single command line text prompt. You have icons to represent running programs instead of long commands.
An OS can also act as a central manager for your computer. It can clean up files, fix your computer and run anti-virus checks. It also stops the user from doing potentially harmful things to the computer, such as deleting important files. It also controls what applications can do what, you don’t want a calculator accessing your camera.
Most importantly, an OS allows for a computer to appear to do more than one thing at a time. Before OS, computers could only run the program that was selected. What an OS can do is give one program a bit of time to run, then give the other program time. It does it so fast that it seems that they’re running at the same time. It is how your able to have music running in the background as you scroll Reddit, or use multiple windows on a computer. (This is how Windows got its name, from this ability to have applications run in different windows, it was that revolutionary)
We don’t need it, but it makes things a lot easier.
Years and years ago there was no OS like we know it. You could run just one program at a time and that program had to do almost everything by itself. There was Basic Input-Output System (BIOS) that let you read the keyboard and display text on the monitor but that was it.
You want to display an image? You’d need to program that yourself.
The OS let you do all those basic things like reading a file or displaying an image by just asking it nicely to do it for your program.
Then the computers become more and mor powerful and OS let several programs run at at same time. Talk to the disk. Communicate over network. Play sound. Your program didn’t need to know how to do that, it could just tell the OS to do it.
A computer can do many things. It moves electricity around to make things happen. It does what it’s told to do,
The computer can take instructions from many sources, but what you want the computer to do helps determine where you want the instructions to come from.
An operating system takes responsibility for interfacing with the hardware of the computer so that applications don’t have to.
Applications are built for an operating system in order to take advantage of the simplification provided by letting the OS do what it does. It’s more scalable. Many applications can be built for the same hardware.
It’s the mother program that runs and commands the hardware and let other children programs run. Other children program children don’t have to think about how all of that magic is happening.
A computer consists of hardware and software. Without either, there’s no computer. Hardware itself is mechanics and electrical signals (mainly the latter today) – hardware doesn’t talk “human” – there’s nothing on your screen with just hardware, there’s no files, there’s no keyboard, letters – all of that is software. Software defines this – software is what defines what a file is, what the letter A looks like, knows how to make the hardware understands when you write 10+10, so it can do the calculation. It’s all software.
But most programmers (very few do) today write the code at this low level. The interface between the application software you use and the hardware is the OS. The programmer builds on the OS, not the hardware. And because there are so many different kinds of hardware, the OS also allows the same program to run on lots of different hardware platforms, as the OS abstracts the complexity from the programmer.
All of that, and more, you can find on lots of web sites, in books etc. If this subject has your interest, I highly recommend starting there. You’ll get a lot more than these short reddit replies to help you understand both hardware and software.
Imagine you’re writing a really simple app on a phone.
If you started with nothing, you would need to write all the software to deal with detecting finger swipes, providing a keyboard for users to type into, a way to draw something on the screen, etc. You’d (probably) years of work before you even started working on your app.
Instead, you get to start that stuff done already for you. And everyone else can start with it too.
That’s an OS.
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