Optical storage devices use laser technology to 'read' the data stored. A CD converts the data(music, video etc) into a long list of binary code. This binary code is stored through 'land' and 'pits'. Pits or bumps are small holes that are made through a laser onto the CD. They represent the zero of the binary code. The land is the unchanged part of the CD and this represents the 1 of the binary code. This process is called 'burning'. This code is later read by another laser which converts the data into the required format.
Today, computers have changed since their inception by allowing for more memory space. Sometimes, nowadays there is not enough space on a computer to save all of your files. Sometimes, you have to save everything to a flash drive. However, sometimes, they get full too. When someone wants an optical storage device, then they need a disc drive to save the extra data that they would have saved on their computer.
They may want to have access to the information at a later time. Therefore, they may attack an optical storage device like those that can read CD’s. Magnetism is key when it comes to this type of storage. The amount of storage that these can hold varies from relatively small amount of storage to a large amount.