The vast majority of TVs sold over recent years have been 'HD ready', which means that they can accept signals from an EXTERNAL HD source (such as a Blu-ray disc). As those TV s were coming onto the market at the same time as the digital switchover was announced, they also featured an 'ORDINARY' Freeview tuner (because terrestrial HD transmissions were still in development). Such TVs have this logo on the box:
http://www.bitterwall.../01/freeview-logo.jpg
together with this one:
http://typophile.com/...HD%20Ready%20Logo.jpg
With the advent of terrestrial HD TV (i.e. Freeview HD), some TVs now have an HD tuner built into them. They're generally more expensive and they can be identified by this logo on the box:
http://www.cnet.co.uk.../freeview_hd_logo.jpg
With the former type of TV you'll need an external source (i.e. a Freeview HD set-top box) to view Freeview HD transmissions. With the latter type you won't.
Chris