According to Wikipedia:
In computer science and information theory, a Huffman code is a particular type of optimal prefix code that is commonly used for lossless data compression. The output from Huffman's algorithm can be viewed as a variable-length code table for encoding a source symbol (such as a character in a file). The algorithm derives this table from the estimated probability or frequency of occurrence (weight) for each possible value of the source symbol. As in other entropy encoding methods, more common symbols are generall represented using fewer bits than less common symbols.
