Film Glossary

Blu-ray players are the successor to DVD, and allow you to enjoy your favourite films with unparalleled picture and sound quality. They can play all your old DVDs, as well as the new Blu-ray disc format.

Blu-ray players are so named because they read discs using a blue laser, unlike CD or DVD players, which use a red laser. Because blue light has a shorter wavelength than red light this means that more information can be stored on a single disc. So whilst Blu-ray discs are the same physical size as standard DVDs, they can hold almost six times the amount of data.

Like DVDs, Blu-ray discs can be either single or double-layered, with double-layered discs comprising two layers of information, one on top of the other. These two layers are invisible to the naked eye and Blu-ray players can switch between them seamlessly during playback (double-layered discs should not be confused with double-sided discs, which are extremely rare).

In total, a double-layered DVD disc holds around 8.5 gigabytes (GB) of information, whilst a double-layered Blu-ray disc holds 50 GB. In theory, this means that a 5 disc DVD set of your favourite TV show could fit onto a single Blu-ray disc. In practice, however, the extra space is used to store the same footage in a much higher quality, meaning that DVD and Blu-ray box sets usually contain the same number of discs.

Whilst a DVD player can output video at a resolution of 720 x 480 pixels, Blu-ray players can output at a resolution of up to 1920 x 1080, which is very close to the quality of projected 35mm film. However, standard-definition televisions are unable to display resolutions above DVD resolution, so to make full use of a Blu-ray player you also need a high definition television (HDTV) connected via a HDMI cable (HDMI cables can be exorbitantly expensive, but they all deliver the same picture quality regardless of price).

The first Blu-ray player was released back in June 2006 by Sony, one of the founding members of the Blu-ray Disc Association, a consortium of manufacturers and film studios who developed the standard (a similar group, the DVD Forum, exists to develop the DVD standard). Since then, Blu-ray players have become available from a range of manufacturers, and Blu-ray drives are also found in laptops, computers, and Sony's PlayStation 3 videogames console.

Most current Blu-ray players are Profile 1.2, also called BD-Live, which means they can connect to the internet to download extra content and offer interactive online features. Older Blu-ray players may not support these extras, but they will always be able to play the main feature on the disc.

Like DVD players, Blu-ray players are split into geographic regions: Region A covers the Americas and East Asia, Region B covers Europe, Africa and Australia, and Region C covers Russia and Central/South Asia. A Region B Blu-ray disc will not play in a Region A Blu-ray player, and vice versa. However, a large number of Blu-ray discs are currently Region-Free, meaning they can be played in any Blu-ray player.

In addition, Blu-ray players can play ordinary DVDs, and many are capable of enhancing the DVD image so it looks better on a HDTV, a process called 'upscaling'. So, unlike the move from VHS to DVD, your old DVD collection won't be obsolete overnight!