Audio cd :- Used to store music better quality then
normal cassette’s. & It has longer life.
It can store up to 74min of music.
Cd Rom :- Used to store data and other files. such as
data base & world processors.
It can also hold music & movie files.
It can only read.
Cd-R :- Once written cannot be erased.
Useful to backup data.
used to create music cd’s.
Special layer between polycorbonate and
aluminum layer to store data.
Made up of photosynthetic dye.
Cd-Rw:- It can erase it and write again.
Used to transfer the data form one system to
Has special layer called phase change compound
layer that makes it possible to Rewrite the data.
Polycarbonate layer:- Transparent plastic layer.
It protects data.
Aluminum layer :- Reflects laser beam from the cd.
Applied on cd containing of argon.
Stores data in this layer.
Acrylic layer :- Final layer
Protects aluminum and
Label layer :- On the top of acrylic layer.
Used to print the description.
Original speed of the C.D.drive is 150kbps.
C.Ddrive spins the cd like a wheel and
read’s data form the cd using a laser
Cd-Rom drive:- Can read data from cd-Rom audio cd.
Ex :- 52x specified that 52x150=93,600kbps.
Cd-R drive :- It Can read data from cd-Rom Audio
cd and cd-R disk.
It can also write data to cd-R
In single session data is written and
closed cannot write again.
In multiple session data can be added
speed specifies using 2no’s
Ex :- 53x – 12x