To view HD content, you need a screen that can display the full resolution of the HD content. Some HD ready screens, especially lower-priced plasma screens, can only display 720 lines, so 1080 content has to be down sampled. You also need an HD receiver, for broadcast content, an HD set-top box for cable or satellite HD content, or an HD-DVD or Blu-Ray player for HD content on DVD. VIIV PCs and current Windows Media Center PCs can receive HDTV with the right tuner. Some TVs labelled as "HD ready" have the receiver built in - since March 2006 all 25-35" sets sold in the US must include an HD tuner - but before you pay extra for it, check how the HD content you want to watch is going to be broadcast.

To connect HD devices together you don't use SCART or S video. Although some HD equipment lets you connect via component video or even FireWire, the main connector is High Definition Multimedia Interface (HDMI). This interface supports high-definition sound too: 8-channel 192kHtz uncompressed audio, as well as Dolby Digital and DTS. HDMI 1.3 will support the new Dolby TrueHD and DTS-HD lossless digital audio formats. Confusingly, manufacturers can choose which features of HDMI to implement; if you want a DVD-Audio or SACD connection, check if the HDMI connection on the set you're considering implements it.

For connecting a PC or a high-definition DVD player or set-top box that decodes copy-protected content, you may need High-bandwidth Digital Copy Protection (HDCP). This is a system that applies DRM to a DVI or HDMI connection. The "protected video path" in Windows Vista uses HDCP connections to let you play DRM content but not pirate a copy. Creators of Blu-Ray and HD-DVD discs can choose to set a flag that only lets you play the content in HD via an HDCP connection; if you connect it to a system without HDCP you get a downsampled version instead.