Virtual reality, or VR, has been touted as the next big thing since Pierce Brosnan waded around a virtual world in the 1992 thriller 'The Lawnmower Man'.
Its graphics look awful now, but back in the early '90s they were cutting edge. But then so were Reebok Pumps.
In the end, VR technology failed to take hold back then and it soon faded from view.
But the men and women in laboratories all over the world didn't stop working.
Now VR is enjoying a second coming. And, crucially, the technology is much more advanced.
VR is also a lot more affordable than it was back then, meaning the time is ripe for virtual reality to finally enter our homes.
But what is VR? How does it work? And what options are available to you? Strap on your VR headset, all will be explained.
What is virtual reality?
Put simply, VR is a way of creating a 3D virtual environment that you can then explore and interact with.
Most commonly it's done by strapping on a headset that blocks out external light and shuts you off from the real world.
Screens in front of your eyes show your new environment – be it a fantasy world, a forest, outer space, whatever.
T-he sense of immersion and really 'being there' comes from the fact that the environment is 360-degrees.
Turn your head to the side in real life and the VR screen's perspective changes too. Look behind you and it shifts again. The environment you're exploring really feels like it's all around you.
There are other major differences with VR this time around too.
As anyone who tried out earlier attempts at VR will know, previous headsets suffered from 'lag', where the environment took a while to catch up when you turned your head.
Not only did this ruin the illusion, it also made the wearer feel sick. But this problem has been eliminated with newer headsets.
What is it used for?
The main focus of VR so far is on games.
As you can imagine, immersing players in an interactive 3D environment will make games more realistic than ever before.
Imagine a first-person shooter where you're actually running around the environment, and you can see why people are so excited.
But the uses go far beyond games.
The technology could make films and TV shows much more immersive, as well as websites, apps and pretty much anything you can do with your phone.
Facebook owns Oculus VR, the company largely responsible for the resurgence of virtual reality.
So expect social networking to get a more immersive feel in the future.
More and more companies are releasing wearable cameras that record 360-degree footage too, which you can then watch back through a virtual reality headset.
This means you can capture footage of you surfing, paintballing, or just going to the shops, and watch it back in VR later, turning your head any which way to see things that you missed first time around.
Which VR headsets are available? Which ones work with smartphones?
Since the Oculus Rift VR headset raised over $2 million on crowdfunding site Kickstarter back in 2012, lots of manufacturers have launched virtual reality goggles.
The Rift is priced £499. The HTC Vive is more expensive, at £689.
These prices don't take into account the powerful PC you'll need to run them, however. That's something we'll look at in the next section.
At £80, the Samsung Gear VR is one of the cheaper headsets around. You also don't need a PC, which will save you a lot of money.
However, you will need a Samsung phone to slot into the Gear VR – either the Galaxy S6, S6 Edge, S6 Edge Plus, Note 5, S7 or S7 Edge.
Because the Gear VR uses the phone screen positioned really close to your eyes to create a virtual reality environment, it's not quite as engrossing as a 'true' VR headset like the Rift or HTC Vive.
Games companies have also launched VR headset. Sony's PlayStation VR works with the PlayStation 4 and PlayStation Vita.
It's expected to launch in the first half of this year, though Sony is yet to announce an exact release date and price.
If you want VR on the cheap, you can pick up a Google Cardboard headset for just a few quid.
It does the same basic job as the Samsung Gear VR, but works with more phones than just Samsung ones. It's also made of cardboard, so the build quality won't be fantastic.
The Microsoft HoloLens is a little different to these. Which explains why it costs around £2,000.
We'll come onto that in the 'How does VR differ from augmented reality?' section.
As you can see, there's no shortage of VR headsets on offer. Even McDonalds is in on it!
What else do I need?
If you want a 'true' virtual reality experience, you'll need a high-end PC to plug the headset into.
To run the Oculus Rift, Oculus recommends you have a PC with an Nvidia GTX 970/AMD R9 290 video card or equivalent, Intel i5-4590 graphics card or equivalent, 8GB of RAM, HDMI 1.3 video output, three USB 3.0 ports and one USB 2.0 port, and Windows 7 SP1 64-bit or newer operating system.
The good news is that Oculus will offer money off certain PCs that have these specs when bought with an Oculus Rift.
The bad news? It'll still set you back around £1,000, before you add the £499 for the headset.
The HTC Vive needs a similarly high-specced PC. The video and graphics card will have to be the same level as that to run the Oculus Rift, but it only needs 4GB of RAM, not 8GB.
The video output needs to be HDMI 1.4, but you only need one USB port at 2.0 or better. The operating system requirement is the same.
Content is king, as everyone knows. Sadly in the case of virtual reality, there's not too much of it about at the moment.
Companies are keen to show off demos, and some games will launch in VR.
But until the prices of the headsets come down and they're more widely available, expect content to be relatively thin on the ground.
Our prediction? The really good content won't start arriving until next year.
That said, there are some pretty impressive YouTube 360-degree videos you can watch using a Samsung Gear VR or Google Cardboard headset.
While they're not interactive, they do let you turn your head and look around the environment as if you were there.
Check out the video below in full screen in your web browser for a taster.
Note: not all browsers support 360-degree videos, so make sure you're using a compatible one like Google Chrome.
Now imagine that using a headset where that's all you can see. Pretty cool, eh?
How does VR differ from augmented reality?
Augmented reality is a little different. Instead of cutting you off from the real world and creating a completely virtual environment, it superimposes virtual elements onto your view of the real world (i.e. whatever is in front of you).
The best demo of this is Microsoft's HoloLens.
As you can see, this has amazing potential for gaming, as the enemies enter your real-world environment.
But it could also be used to create virtual screens on walls that only you can see, which would be very useful for working (or slacking off, if you're that way inclined).
The first HoloLens sets are being sent out to developers now, but an actual consumer release is still some way away.
Want a sneak peek at the future? Check out this demo by augmented reality firm Magic Leap.
Make no mistake, this technology is going to be huge. But it might take a price drop for that to happen.