What is Data Compression? Data compression is the process of reducing the size of a file or data stream. This is done to save storage space or reduce transmission time.

Why Compress Data?

• Storage Efficiency: Saves space on storage devices.
• Transmission Speed: Reduces the time required to send data over a network.
• Cost Reduction: Less storage and bandwidth usage can lower costs.

Types of Data Compression

• Lossless Compression: No data is lost; the original data can be perfectly reconstructed.
• Lossy Compression: Some data is lost; the original data cannot be perfectly reconstructed but is approximated (”close enough”).

Huffman Coding

What is Huffman Coding?

Huffman coding is a method of lossless data compression. It uses variable-length codes to represent characters, with shorter codes assigned to more frequent characters.

How do I make a Huffman tree?

Let’s try to encode the string "AQA Extreme Exams" into Huffman coding.

Step 1: Start with a list of characters and their frequencies.