HD leads are the only leads you need to bring out the best in your High Definition equipment. Up until recently, before HD leads set the standard and then became the standard, the back of your TV set would have been a real mess. In order to connect your TV to all your other devices you would have needed any combination of SCART, S-video, Audio and VGA cables which could be confusing as well as unattractive. HD leads do the business for all your gadgets, one of your HD leads between two devices is all you need.
You can use HD leads for almost anything. Connecting your BluRay player is arguably the most obvious function of HD leads because only HD leads enable you to see your content in all of its High Definition glory. HD leads transmit uncompressed digital data which means there is no loss of quality between devices. This applies to HD TV too, without HD leads connecting your HD Freeview, Freesat or Sky HD you simply will not get the crystal clarity you have paid for. Even games consoles like Xbox and PS3 depend on HD leads so that you can play your games with the detail the makers intended.