Smart TV is the catch-all term for TVs that can be connected to the Internet and your home network to access online services or stream films and music from your PC.
At present there's no standard smart TV system. All manufacturers offer their own smart TV platforms. These are essentially TV operating systems with different user interfaces, features and functionality. They aren't always as slick as they could be and are often sluggish to use -- some companies clearly do it better than others.
Most of today's smart TVs now come with a range of apps pre-loaded and you can often download additional ones via built-in app stores. The vast majority of these apps are free, though some -- often games -- have to be paid for.
Even on the most basic smart TV services you'll find an app that allows you to access the BBC's iPlayer as well as the YouTube video website. Often apps for Facebook and Twitter are included too. The more advanced the smart TV platform, the more services that will be on offer.
Unfortunately, although the BBC iPlayer app is widely supported, services form other UK broadcasters such as Channel 4's 4oD and ITV Player are yet to appear on any smart TV platform, while Channel 5's Demand 5 is only available on Sony models.
Nevertheless, the Netflix TV and movie on-demand service is fairly widely available and Lovefilm is gradually gaining ground. You'll also find the Acetrax movie rental service on many smart TVs and competing services such as Blinkbox and FetchTV.
The big name manufacturers like Sony, Panasonic, LG and Samsung tend to include a range of news and information services such as a BBC News app and the Eurosports video news service, as well as the AccuWeather forecast app. You'll also find some simple games included, although the quality lags far behind what you'd get on even today's most basic smart phones.
Browsing the Internet
Increasingly, manufacturers are adding full web browsers to their TVs, so you can visit standard websites, rather than just being limited to a 'walled garden' of Internet content. This often sounds better on paper than it is in practice. Navigating websites with a standard remote -- or even using the new motion controllers or touchpad zappers that smart TV manufacturers are increasingly supplying with their sets -- can be a slow and tortuous experience.
It's also rare for these web browsers to support embedded video on websites, which is actually what you really want a browser on a TV to do. That said, some brands offer free smart phone and tablet apps that you can use to 'catch and throw' web pages to the TV. Put simply, you call up the web page on your smart phone, then using a touch gesture, send it to the browser on the TV over Wi-Fi to view it on the large screen.
These smart phone apps also usually double up as 'network' remote controls for the TV, allowing you to change channels, adjust the volume and switch inputs, just as you would with a standard remote. LG and Samsung have also recently offered voice control and Kinect-style motion-sensing on their high-end models, although we found the results to be mixed.
As well Internet features, smart TVs also tend to allow you to stream your own video files across a network from a PC, networked hard drive or smart phone, or to play them from memory keys and hard drives attached to USB ports. Unfortunately, although format support has been improving gradually, it can still be very mixed. Sometimes a TV will play a video file, such as MKV, via USB but it will refuse to stream the same format across a network.
Cheaper smart TVs usually only include a wired Ethernet port on the rear for networking with your computer, but from mid-2012 onwards, most mid-range and higher-end models will have Wi-Fi built-in. Wi-Fi is naturally more convenient to use as it means you don't have to run a cable from your router to your TV to get connected.
It's worth bearing in mind that you can use a Wi-Fi bridge or Powerline Ethernet adaptors with sets that don't have onboard Wi-Fi, although this does make setting them up more difficult. You'd also have to factor in the expense of this extra hardware.
Below, you'll find a selection of the best-selling and top-rated smart TVs that we've cast our critical eyes over. Of course, because they're the best, they tend to be at the pricier end of the scale. That's not to say you can't find decent models for under £1,000. The £650 Panasonic TX-L32ET5B is a case in point, while Samsung and LG have models starting from £450.