[FFmpeg-user] Questions about Global Tags and Tags

[Springhill NS Rental]

Hello,

I ran a command such as this 

ffmpeg -y -I input.mkv -map 0:v -c:v copy -map 0:a -c:a:0 copy -map 0:a -c:a:1 ac3 -map 0:s:1 -c:s:1 copy output.mkv 

When I view, the output.mkv in MKVToolNix GUI program, I see this



Can someone explain me what are Global Tags and Tags are? I didn’t add them.

Also SubRip/SRT is displayed as SubStationAlpha. What is causing this renaming? How can I keep the same name?

Thanks in advance for your time and help.

Joe