Solved Windows 8/Pre installed AntiVirus

I'm hoping someone can help to answer the simplest of questions. Unfortunately I am the beginner of all 'beginners' and have only just gone further than 'laptop on/laptop off', so basically 'I'm clueless.
Wanting to 'keep up with the times' I've decided to treat myself to a new, more up-to-date laptop running Windows 8. I've been browsing online and noticed a few stating that windows 8 comes with a pre-installed antivirus? By 'pre-installed', am I rite in thinking that with windows 8 there is no need to buy additional antivirus software? And would this be an ongoing thing, or would I have to pay to keep the antivirus running? And with the antivirus being pre-installed, would I still be able to change the antivirus provider if I felt the need to?

Kind regards
Over-my-head

When you buy a laptop with Windows 8/8.1 installed on it (you'll be getting 8.1 rather than 8, BTW), then the bare minimum you'll get is Windows Defender, which is an anti-virus application from Microsoft that's built into the operating system. This is free and gets automatic definition updates. Mind you, you'll likely find that the company that's supplied you the laptop will have "helpfully" included a third-party anti-virus, which is supplied on a trial basis for about a month or so. This is due to a deal being struck by the anti-virus company and the company that's manufactured/sold the laptop. It might be of interest to you, but it might not be; your choice. Still, when that expires (if it's installed), then if you don't want to keep on using that anti-virus, you can always remove it and Windows Defender should take over (Windows Defender disables itself when another anti-virus application is installed, but gets enabled when it's the sole anti-virus on the machine... or should do).

Bear in mind that Windows Defender is seen by many as a minimal choice and many do recommend going for a third party anti-virus application. However, if you're not surfing into dangerous territory and installing iffy applications, then Windows Defender should be adequate (think about installing Malwarebytes alongside it, which is not a substitute for anti-virus but helps tackle malware that many anti-virus applications don't focus on).

So, yeah, you're covered for anti-virus by default when you buy a laptop with Windows 8/8.1 installed.

Thank you very much, much clearer understanding now.