The greatest value digital brings to audiences is the ability to view high definition content. Even as the broadcast signal moves from analogue to digital, we are slowly seeing HD DVD and Blu-Ray devices emerging. These forms of video content show considerably more than standard-definition television (SDTV). For those wondering what to buy, there are three numbers worth thinking about (they all refer to the number of vertical lines). By far the best is 1,080p. PCCW's Now TV Broadband can handle 720p, and experts say it's difficult to see the difference between that and 1,080i (see below). Another point to remember is that the flat screen TVs are all set up to have an aspect ratio (width divided by height) of 16:9. The old SDTV was nearly square at 4:3. The new aspect ratio is much more like a cinema screen, and it will make viewing films more enjoyable. At a glance 720p 720 lines progressive scan 1,080i 1,080 lines interlaced 1,080p 1,080 lines progressive scan