The Full Form of HDA is High Definition Audio.

Intel has worked with the industry to develop a new specification for integrated audio that is capable of delivering the features and high-end performance of an add-in audio card. Intel® High Definition Audio (Intel® HD Audio) is capable of playing back more channels at higher quality than previous integrated audio formats. In addition, Intel® High Definition Audio (Intel® HD Audio) has the technology needed to support the latest and greatest audio content. By enabling enhanced usage models, Intel® High Definition Audio (Intel® HD Audio), available with the Intel® Express Chipsets, will also change how computer users interact with sound.

Intel® High Definition Audio (Intel® HD Audio) delivers significant improvements over previous generation integrated audio and sound cards. Intel® High Definition Audio (Intel® HD Audio) hardware is capable of delivering the support and sound quality for up to eight channels at 192 kHz/32-bit quality, while the Analog Codec ’97 specification can only support six channels at 48 kHz/20-bit. In addition, Intel® High Definition Audio (Intel® HD Audio) is architected to prevent the occasional glitches or pops that other audio solutions can have by providing dedicated system bandwidth for critical audio functions.