AAC is the abbreviation for Advanced Audio Coding, a lossy digital audio data compression and encoding system developed by the MPEG group, as the basis of MPEG-4 and other Internet, wireless, and digital broadcast systems, and intended as the successor to MP3. Claimed improvements over MP3 include more (and higher) sample frequencies, up to 48 channels, increased coding efficiency, improved high-frequency response over 16 kHz, and more. A wide variety of hardware and software devices support AAC, most notably Apple’s iTunes and iPods.
IAC, the short for Inter-Application Communication is a driver developed by Apple for their machines / operating systems which gives the possibility to different software apps that were running on the same computer to be synchronized and share data between.
AIFF is the abbreviation for Audio Interchange File Format. The term “AIFF” refers to that audio file format standard developed by Apple in 1988 after Electronic Arts Interchange File Format known as IFF. The extension of this standard is .aiff or .aif and it can be found as being used mostly on Apple powered computer systems. Along with SDII and also WAV, AIFF standard is leading format used by pro audio and pro video applications because it is uncompressed and also lossless.