Audio and video formats are specific ways that sound and visual information are encoded for storage and playback. Common audio formats include MP3, WAV, and AAC, while popular video formats include MP4, AVI, and MOV. Each format has its own characteristics, such as file size, quality, and compatibility with different devices. These formats determine how media files are compressed and decompressed, affecting their quality and size. For instance, MP3 files are compressed to save space but may lose some audio quality, whereas WAV files retain high quality but take up more storage. Understanding these formats helps users choose the best option for their needs.