1.3 Data Compression

Removes redundant or unnecessary data permanently to reduce the file size. Commonly used for multimedia files like audio, video, and images. For example, in a music file, it may remove background noise not easily audible to the human ear.

Does not lose data during compression. It can reconstruct the original data file exactly. For example, in a text file, it may store repeating words and their positions. Consider the message "WHEN IT IS SNOWING HEAVILY LOOK OUTSIDE. LOOK OUTSIDE IT IS SNOWING HEAVILY." which can be compressed by storing the words and their positions.