These days all HD and Full HD televisions should come with a built-in HD tuner, which lets you watch stand-def and high-def digital channels.
Watch out for the blue 'Digital Capable' sticker, which means it doesn't have digital tuners. The yellow ‘Digital Ready - Standard Definition' sticker means it only has standard-def digital tuners, while the purple ‘Digital Ready - High Definition' sticker means you can get all the new standard and high-def channels.
The old labelling systems were also deceptive, as ‘HD Ready' could mean it was a 720p television with HD-capable inputs but it only featured standard-def or analogue tuners.
Features such as Picture-in-Picture require two tuners, but some televisions come with one digital tuner and one analogue - this latter of which will be rendered useless when analogue broadcasts cease.
Australian digital television is currently broadcast using the MPEG-2 compression format, although eventually it may switch to the more bandwidth-efficient MPEG-4 which is not backwards compatible, so devices with MPEG-2-only tuners will be useless.
This is unlikely to happen before 2014. Any television with a Freeview logo must include an MPEG-4-compatible tuner, although some models from the likes of LG, Panasonic, Philips, Samsung, Pioneer, Sharp, Sony and Toshiba are already MPEG-4 compatible. Due to the expense of licensing the technology, budget televisions are less likely to be MPEG-4 compatible.
Also in this series, How to Pick a Great Flat Screen TV, And Not Get Sucked In By Marketing Hype:
Part 5: HDMI and component ports
Part 4: LED and backlighting
Part 3: Screen size
Part 2: Refresh rates
Part 1: Brightness and contrast ratios
Also see our 5 tips for buying a digital TV set top box
And also see the lowdown on Freeview, and whether you should care
If you're new to Digital TV, or have yet to make the leap, start by reading Prepare yourself for Digital TV