Represents the mechanism by rotating the plate saved through reading or recording head (read/write head) causes. The data can be saved in the plate save process. If you want to save the new data, you can save it as well.
The mechanism of the rotating disk through the head or heads (read / write head) could make the information stored on the disk to process it. If you want to save the new data, it can be saved as well.
Means the disk to rotate the mechanism through the head or the recording head (read / write head) makes the information recorded in the disk processing. If you want to save the new data into it can be saved as well.