Pieces (4)
'pieces' is the definition.
('bit' can be a synonym of 'piece')
This is the entire clue.
(Other definitions for bits that I've seen before include "Small pieces" , "Pieces, fragments" , "Parts" , "Small units of digital memory" .)
'pieces' is the definition.
(fragment is a kind of piece)
This is all the clue.
(Another definition for fragments that I've seen is " 'Small pieces, perhaps broken (9)'".)