The data storage hierarchy consists of :

Concept — In data processing, data is organised as an ascending hierarchy in which every level is formed by grouping units of the level immediately below it. The ordering rule is purely compositional: a unit can be named only after the smaller unit it is assembled from, so the sequence always runs from the smallest indivisible unit up to the largest integrated collection.

Application — The six levels named in this question, arranged by that rule:

1. Bit — a single binary digit, 0 or 1. It is the smallest unit of storage and is not composed of anything smaller.

2. Byte — a group of 8 bits; the amount of storage that holds one character, such as "A" or "7".

3. Field — a group of characters (bytes) that records one attribute of an entity, for example a Roll Number field.

4. Record — a set of related fields describing one complete entity, for example all the fields of one student.

5. File — a collection of related records of the same kind, for example the records of every student in a class.

6. Database — an integrated collection of related files, for example the student, course and fee files of a college held and managed together.

Cross-check — Apply the "is built from" test at every junction; each level must follow the unit it is made of.

Every junction in the table points the same way, so the ascending data storage hierarchy is bit → byte → field → record → file → database. A listing that names bytes before bits, records before fields, or files before records breaks this relation, because the larger unit would then appear before the unit it is assembled from.