This document discusses various media compression techniques including JPEG for images, MP3 and AAC for audio, and MPEG standards for video. JPEG takes advantage of human insensitivity to high spatial frequencies to compress images. MP3 audio compression utilizes properties of human hearing like insensitivity to quiet frequencies. MPEG video standards like H.261 and MPEG-2 achieve higher compression by exploiting both spatial and temporal redundancy between frames.