The term in your search likely refers to Advanced Audio Coding . In the context of digital media and file sharing, it indicates that the episode's audio has been compressed using the AAC codec.
Now, about that AAC in your file name. AAC stands for . It’s a digital audio compression standard that’s the successor to MP3. When you see Young.Sheldon.S01E03.AAC.mkv (or .mp4 ), it simply means: young sheldon s01e03 aac
If you’re collecting Young Sheldon episodes and want consistent audio, look for releases labeled AAC 2.0 (stereo) or AAC 5.1 (surround sound). Avoid ancient MP3 audio tracks in video files—they’re a sign of a low-quality encode. The term in your search likely refers to