Huffman Coding:

An entropy encoding algorithm.
It uses variable length code table for encoding source symbol. 

Shannon Fano Coding:

It is used to construct a prefix code that is based on a set of symbols.
It suboptimal. The lowest expected code word length will not be achieved.

Arithmetic Coding:

A variable-length entropy encoding form.
It is used for implementing loss less data compression.
Fewer bits are occupied when frequently used characters are represented. More bits are occupied when not-so-frequently used characters are represented.   _{Your Comment}