Data hierarchy is a systematic organization of data mainly in a hierarchical form. Data organisation basically involves fields, records, files and so on.
So different levels of Data Hierarchy are:
1) Bit: A bit is the smallest unit of the data in a computer and a bit has a single binary value either 0 or 1.
2) Character: It is a single visual object used to represent text, numbers or symbols. And set of character become characters.
Example : K,j,a,O= Letters
+,-= special symbols
@,%= special symbols
1 character is equal to 8 bits = 1 bytes.