HD TV – The Basics Explained
Need a little help with HD? On this page, we offer some help with the High Definition basics, and help you tell your HDMI from your 720p
What is HD?
HD stands for High Definition – HD TV offers higher-quality pictures, greater detail and crisp, vibrant colours.
A standard TV picture is made up of 576 horizontal lines, but an HD TV picture uses either 720 or 1080 horizontal lines to give you the picture improvements.
What does 720 or 1080 resolution mean?
There are four formats of HD:
- 720i – 720 horizontal lines that are interlaced
- 720p – 720 horizontal lines using progressive scanning
- 1080i – 1080 horizontal lines that are interlaced
- 1080p – 1080 horizontal lines using progressive scanning. Known as “Full HD”
In general, it’s fair to say that 1080 lines is better than 720
Progressive and Interlaced refer to how the picture is drawn on screen. Progressive draws the picture in one go. Interlaced draws odd-numbered lines, then even-numbered lines. Progressive is better.
What does ‘HD-Ready’ mean?
This terms is used to describe a type of TV set. For example, “this is an HD-Ready LCD TV set”
This means that the TV is capable of showing a High Definition picture, when connected to an HD source.
- An HD-ready TV can only watch HD content when connected to an HD TV box (e.g. Freeview HD, Sky+HD or Virgin HD box), or a Blu-Ray player, HD-enabled computer or HD-enabled games console.
- An HD-Ready TV set cannot get Freeview HD, Sky HD, Virgin HD or Freesat HD until it is connected to a working HD receiver.
What does ‘Full HD’ mean?
If a TV is referred to as “Full HD”, this means that it can handle the maximum resolution of HD picture available. “Full HD” means that the TV can draw a 1080p HD image. See “What does 720 and 1080 mean?” above.
Full HD does not mean that a TV has a Freeview HD, Freesat HD or Sky HD receiver built in. It refers to the screen resolution and format.
What is HDMI?
This refers to the type of connector used by HD equipment. Typically, you get an HDMI lead to connect an HD receiver box or Blue-Ray player to an HD-Ready TV set.
See our HDMI Information page for full details and help on using HDMI
What is Freeview HD?
Freeview HD launched in December 2009.
To get Freeview HD, you need either:
- a) An HD TV that has a built-in Freeview HD tuner, or
- b) an HD-Ready TV connected to a Freeview HD box. You also need to be in a Freeview HD coverage area
Note: If you have an HD-ready TV with built-in Freeview, this does not necessarily mean that you can get Freeview HD. Freeview HD uses a new technology, DVB-T2. HD TV sets sold before 2010 do not include this technology. Look for an “HD TV with build-in Freeview HD”.
We have a number of pages dedicated to Freeview HD. Please select one of the following:
- Looking for information on Freeview HD and how to get it? See our Freeview HD page
- Looking for a Freeview HD box, recorder or TV? See our Freeview HD boxes page
- Got a question about Freeview HD? See our Freeview HD Help and Advice page
How do I get Sky HD?
Looking for information on Sky+HD? See our dedicated Sky+HD page, or see Sky’s HD site
HD Channels
Looking for a list of HD channels available in the UK? See our UK HD Channels Table
Other HD Pages
