This document discusses Huffman coding, which is a technique used to compress files for transmission by assigning variable length codes to characters based on their frequency of occurrence. It provides details on how a Huffman tree is constructed by first counting character frequencies, prioritizing characters by frequency, and building the tree by combining the lowest frequency nodes. The tree is then traversed to determine the code words for each character. When encoding a file, the characters are replaced with their code words to create a more compact representation. Decoding works by using the same tree to map the code words back to characters. Huffman coding results in significant data compression by assigning shorter codes to more common characters.