Advanced Audio Coding (AAC) is a standardized, lossy audio compression and encoding scheme for digital audio. Designed to be the successor to MP3, AAC generally achieves better sound quality than MP3 at similar bit rates. It is widely used as the default audio format for YouTube, iOS devices, Android, Nintendo platforms, and PlayStation. AAC is part of the MPEG-4 standard (ISO/IEC 14496-3) and is also specified in ISO/IEC 13818-7 (MPEG-2 Part 7). AAC supports a wide range of sample rates and bit rates, allowing for flexibility in balancing audio quality and file size. Different profiles of AAC exist, such as AAC-LC (Low Complexity), AAC-HE (High-Efficiency), and AAC-LD (Low Delay), each optimized for different applications. AAC-LC is the most common profile, while AAC-HE is designed for low bit rate streaming. AAC-LD is used in applications requiring minimal delay, such as teleconferencing. The file extension '.aac' is commonly used to denote raw AAC audio streams, but AAC audio is often embedded within container formats like MP4 (.mp4, .m4a) and 3GP (.3gp).