Forward and backward link bytes are used to maintain a data structure called a linked list, which can be envisioned as links in a chain. Each link is attached to two other links—one in front and one behind.
By linking frames together in this fashion, D3 can store data larger than the capacity of a single frame even though the linked frames are scattered around the disk drive or drives.
Note that it is faster to grab nn contiguous frames than it is to grab one frame, read the forward link, get the next frame, read it, and so on.
See Also