During CES 2018, Nvidia announced that its GeForce Now cloud gaming service is now available to PC and Mac users as a public beta for free.

You have to register and wait for approval, but users in the US and Europe can access it at no extra cost.

There's just one thing; Nvidia GeForce Now for PC and Mac is not the same as Nvidia GeForce Now for Shield TV. They are both very different services. But as they each go by the same name, you can be forgiven for being a little confused.

So what is GeForce Now and what are the differences between the two versions?

Nvidia GeForce Now for Shield devices was originally launched as Nvidia Grid and is the company's answer to PlayStation Now. It is a cloud gaming service that gives access to games stored on dedicated GeForce graphics-enabled PCs which can be played on an Nvidia Shield TV box or Shield Tablet.

It runs on servers using Pascal-based PCs and up to GTX 1080 graphics, so it is capable of running games at their best and streaming them to your device.

The PC and Mac version of GeForce Now is very different.

It gives access to select games bought through Steam, GOG, Origin, Ubisoft's Uplay and other online hubs to play whenever and wherever you want. The games are also be played on a GTX 1080 PC, to give you the very best experience no matter what computer you are streaming them to.

It also means you can play high-end PC games on an Apple Mac, without having to invest in any new hardware.

For both versions of GeForce Now, the games are stored and played remotely and video up to 1080p and in 60 frames per second is streamed to your device with control codes being sent in the opposite direction over the internet. It is an extremely low latency service so there is very little lag and it responds as if the game were stored directly on your device. In many ways, you can't tell the difference.

The Nvidia GeForce Now service is available on the current Shield TV and Shield Tablet devices. The new version is available as a free beta at present - just head to nvidia.com to sign up.

Once formally registered, it will just require the download of an application for your PC or Mac.

The latest Shield Android TV user interface has GeForce Now games integrated into its design and can be found under "Nvidia Games".

The Shield version of Nvidia GeForce Now costs £7.49 a month for unlimited access to around 60 games, with more available to purchase outright.

The PC and Mac version is currently free to access during the public beta phase.

It was previously suggested that, when payments are introduced, it could cost from $25 for around 20 hours worth of play.

The big thing about the new GeForce Now is that your own games will be available to you. So if you have a healthy library of games on Steam, Origin, GOG, Uplay or whathaveyou, you can simply install them on the remote machine and play them whenever you fancy.

It dramatically opens up the potential for the service over the 100 titles previously available.

You can the list of currently supported games here.

For Shield TV or Tablet owners, their version of GeForce Now gets plenty of day and date releases, so you can purchase games at the same time they hit the stores.

You can see a list of the supported games on Shield here.

All of your save files are stored in the cloud so you can pick up where you left off whenever you like.

Wi-Fi works well (we had the Shield GeForce Now service running on a Wi-Fi connection in a hotel room with no problems whatsoever) and the absolute minimum broadband speed it will work on is 1.5Mbps. However, Nvidia recommends at least 6.5Mbps if you want to maintain a stable frame rate and ensure that latency is low.

Indeed, it told us that a 10Mbps connection is ideal as then there is enough bandwidth to have at least 6.5Mbps dedicated to the experience with the rest being used by other internet connected devices at the same time.

GeForce Now is now compatible with multiplayer online games too, such as PlayerUnknown's Battlegrounds and Fortnite.

What's more, you can play in multiplayer online worlds alongside players of the PC versions of games.