Now that Sky is heavily advertising its new TV system, Sky Q, we've had many questions about what it offers.

There are lots of components to the Sky Q system, with a main box - either Sky Q Silver or Sky Q box - and separate Sky Q Mini boxes for other rooms. There is also a new Sky Q Hub broadband router, and we explain what everything does in considerable depth in our main "What is Sky Q?" feature.

We are also often asked what Sky Q offers that is different to the existing Sky+HD or Now TV options, and we've answered those questions in our head-to-head comparison, "Now TV vs Sky+HD vs Sky Q: Which Sky package is right for you?"

We've even spent some time with the new Sky Q kit to bring you our opinions ahead of a full, in-depth review.

But one question that gets asked a lot that directly springs from the marketing of Sky Q is, "What is Fluid Viewing?"

That's why we've put together this quick and handy guide that explains the concept of Fluid Viewing and why Sky is using it to describe Sky Q.

From the very beginning, starting at the Sky Q announcement event last year, Sky has described the main selling point of the new system as "Fluid Viewing". It also uses the term on its websites and, most significantly, in its TV advertising.

The adverts even render the concept visually, showing liquid coming out of one TV, travelling through a house, and entering another TV or device. It's arty, but really doesn't explain things that well - especially when the full ad is truncated down to 30 or even 10 seconds.

To be fair to Sky and its ad agency though, it's hard to represent Sky Q's talents without running a simple, dull presentation of "if you press something here, it does something there. And then you can do something like this here". How can that compete with shiny globules of molten entertainment blobbing their way around your carpets?

In an esoteric way, the blobs do represent the idea of Fluid Viewing well, in that something watched in one room can be switched to another. It just tells a small part of the story.

So now down to the technology the ad tried to represent. Fluid Viewing is the term Sky uses for watching content on one device and then picking it up on another.

That's it in a nutshell really. Although it's actually a lot neater than that sounds.

A typical Sky Q system has a main box featuring multiple TV tuners - either the Sky Q Silver box with 12 TV tuners or the standard Sky Q box with eight. You will then likely have one or two Sky Q Mini boxes set up in other rooms, which don't have their own tuners but work exactly like a main Sky Q box by linking to it and streaming video (even recordings) over a home network connection.

A Sky Q app is also available for iPad and Android tablets that works similarly to the main Sky Q experience, even giving you the ability to download and watch your recordings when on your travels.

Fluid Viewing means that shows and movies can be watched on any of these devices at any time, with each picking up where the last left off.

For example, you can watch The Avengers: Age of Ultron in the living room on the main box, switch it off, and continue the film exactly where you left off on a tablet or Sky Q Mini box. Even recordings that are left uncompleted can be picked up again from the last moment when downloaded onto a tablet.

Streaming services such as Netflix and Amazon Prime Instant Video have offered a similar feature for some time, where you can pause a programme or film on a TV app, say, and carry on watching it on another device. However, that doesn't include personal recordings, just content streamed over the internet.

Also, Sky has trademarked the term "Fluid Viewing" so it is unique to Sky Q.

Sadly, the pick-it-up-wherever feature is unique to Sky Q for now. It requires a stable, highly-spec'ed ecosystem rather than just the one box and a separate Sky Go app. You'll have to upgrade to Sky Q for the full-on feature.

Sky Q is now available from Sky's own online store.

As an existing subscriber, you will have already received details on how you can upgrade, with Sky saying that it costs a one-off fee for the hardware, with packages charged at around £12 a month over your existing Sky+HD monthly fee.

There are also different, full pricing details for new customers.

There are two packages available for new customers, one that features a Sky Q or Sky Q Silver box and access to 300+ TV channels. That costs £42 a month.

The other package costs £54 a month, has the same channels but includes a Sky Q Silver box and a Sky Q Mini box.

You can also choose to add Sky Movies for an extra £17 a month or Sky Sports for an extra £25.50 a month. Adding both will set you back an extra £34.50 a month (so at a discount).

The one-off fees for the hardware break down as follows:

If you take the £42 a month Sky Q bundle with Sky Broadband, Sky Movies or Sky Sports, you can get the Sky Q box for £99. The Sky Q Silver box as part of that bundle costs £149.

If you take the Sky Q Silver TV bundle at £54 a month, you can get the Sky Q Silver box and a Sky Q Mini box combined for £99.

If you don't take Sky Broadband, Movies or Sports, you must pay £249 for the Sky Q box or £299 for the Silver box as part of the £42 a month bundle.

The hardware for the £54 a month bundle, when taken without the other Sky add-ons, will cost a combined £299.

Extra Sky Q Mini boxes will cost £99 each.

There is also an installation cost of £50.

A Sky Q Hub router doesn't cost any extra when taken with Sky Broadband or, for existing customers, when upgrading to Sky Q.

To find out more about Sky Q, Fluid Viewing and how to order it, you can visit Sky's dedicated page at sky.com/skyq.

READ: What is Sky Q, how much does it cost and how can I get it?