At the beginning of the disc there is a table of contents (TOC, also known as the System File area of the disc), which stores the start positions of the various tracks, as well as meta information (title, artist) about them and free blocks. Unlike the conventional cassette, a recorded song does not need to be stored as one piece on the disk, it can be stored in several fragments, similar to a hard drive. Early MiniDisc equipment had a fragment granularity of 4 seconds audio. Fragments smaller than the granularity are not kept track of, which may lead to the usable capacity of a disc actually shrinking. No means of defragmenting the disc is provided in consumer grade equipment.