If the computer was an orchestra, the operating system would be the conductor. If it was a group of Kindergartners on a field trip, the OS would be the harried but optimistic Miss Frizzle wannabe. If the computer was a talking animal movie, the OS would be the plucky dog everyone's hoping will make it home safely.

You get the idea.

The computer's a ragtag group of hardware that wouldn't get anywhere without an operating system to lead it. The operating system is just a collection of software utilities that link all those pieces of hardware together. While the CPU does all the dirty work of making calculations and allocating memory, the operating system does the elegant, sophisticated things that coordinate everything together. The operating system

• manages the computer’s hardware and software resources to maximize CPU usage and storage capacity.
• coordinates messages between applications and the computer’s hardware. To do this, the OS needs to make sure that each transaction gets the time it needs from the processor and, if it's interrupted before it's done, gets rescheduled for more CPU time.
• manages any messages traveling between the user and the applications that user's trying to…use.

As for which operating system you want to be the plucky dog of your talking animal film, there are almost as many current operating systems as there are computers, so you have your pick of the litter. The best operating systems can run on hardware from many manufacturers and handle any hardware upgrades you want.

Just off the top of our heads, we can think of:

• iOS, which is the operating system used on all Apple devices.
• Microsoft’s Windows, which can run on any PC—even a Mac
• Android runs on mobile devices and tablets, mostly.
• DOS, which was the original desktop computer-based operating system developed by both IBM and Microsoft. (It's also what Windows is still built on.)
• Linux, built on the same system as iOS (UNIX), is the open-source competitor to "the Man." And by "the Man," we mean enterprise OS-es like DOS and iOS.

But there are hundreds—literally hundreds—more. Prepare to be overwhelmed.