Compare contiguous, linked, and indexed file allocation methods.

Contiguous: file stored in consecutive blocks - simple, fast sequential/random access, but external fragmentation and difficult growth. Linked: blocks form linked list - no external fragmentation, easy growth, but slow random access (must traverse), pointer overhead. Indexed: index block contains pointers to data blocks - efficient random access, no external fragmentation, but index overhead. Modern file systems use variations like extents (contiguous runs) or B-trees.