This denotes 5.1 surround sound , providing a high-fidelity atmospheric experience suitable for home theatre systems.
This indicates the video was sourced directly from a streaming service (WEB-DL) and then "remuxed." A remux takes the raw video and audio streams without re-encoding them, preserving the original quality while changing the container (often to MKV). The Alienist 1x02 WEB-DLMux Ita Eng 5 1 Earine
The second episode, titled originally aired on January 29, 2018. This denotes 5