Cat.s01.720p.web-dl.aac.5.1.esub.x264-hdhub4u.t... | ^hot^

: The audio format. AAC is the codec (Advanced Audio Coding), and 5.1 refers to six-channel surround sound (five speakers and one subwoofer).

While file tags tell you about quality, the content is what matters. Assuming this refers to the gripping crime thriller series Cat : Cat.S01.720p.WEB-DL.AAC.5.1.ESub.x264-HDHub4u.T...