LaCie 400USB - Manual (Page 26)

LaCie d2 DVD ±RW Drive
User Manual page 
Helpful Technical Information
There are important factors to consider when record-
ing video, audio or data to CD or DVD discs. The DVD
media specification provides for two physical sizes: 4.7”
(12cm) and 3.1” (8cm) (both are .47” (1.2cm) thick).
DVD discs are single-sided and can have one (SL) or
two (DL) layers of data.
The amount of data or video that a disc can hold are
dependent upon factors such as the amount of audio and
the degree of compression of the data, video or audio.
When media companies reference the amount
of data that a disc can hold, they represent the total
amount in terms of gigabytes (GB), or a billion bytes
(1000 x 1000 x 1000 bytes). This number, though, is not
the way in which a computer addresses the data; to a
computer the value is binary and larger than a billion
bytes – 1,073,741,824 (1024 x 1024 x 1024 bytes).
4.3. About DVD/CD Available Capacity