What is Operating system?

In plain English

An operating system (often shortened to "OS") is the main piece of software that runs your computer, laptop, tablet or phone. It's the bit that's already there the moment you switch on, before you open anything yourself. On most computers and laptops that's Windows; on most phones and tablets it's Android.

Think of it like the manager of a busy shop. You don't deal with every member of staff directly. You tell the manager what you want, and they organise everyone behind the scenes to make it happen. In the same way, the operating system sits between you and all the parts inside your device. When you tap an icon, type a letter, print a page or join the wi-fi, it's the operating system quietly making the screen, keyboard, printer and internet all work together.

Why it matters

Your operating system is the foundation everything else sits on, so keeping it healthy and up to date matters more than almost anything else on your device. Updates aren't just about new features. They quietly patch security holes that scammers and viruses try to sneak through, which is why an out-of-date computer is a far easier target. It also matters because support has an end date: older versions of Windows eventually stop receiving these safety updates, and once that happens a device can become risky to use for online banking, shopping or email. Knowing which operating system you're on, and whether it's still supported, helps you avoid nasty surprises.

What to do

• Let updates install. When Windows or Android asks to update, say yes (a good moment is overnight or at the end of the day). These are mostly free safety fixes, not sales pitches.
• Don't panic about jargon. You don't need to understand what's inside the update. You just need it to be reasonably current.
• Check you're still supported. If your computer is several years old and feels sluggish or nags that it's no longer updated, it's worth asking someone trustworthy whether it can be updated or should be replaced.
• Be wary of pop-ups claiming your system is "infected" or "out of date" and demanding you call a number or pay. Genuine updates come from Windows or Android themselves, never from a flashing web page.

How 365 Techies can help

If you're unsure which Windows or Android version you're on, or whether your device is still safe to use, we're a friendly local Dorset family firm who can check it over and explain everything in plain English, with no pressure.

Related: App vs program · Driver · BIOS · Malware — or browse the full A–Z jargon buster.