Please help me understand m2ts, m4p, and avi

I guess you could say I'm an idiot because I've been an editor for so many years and now I need help with something so basic as this. But I've always been stuck doing the same thing with the same format and now that I have to work with something else I feel a little stupid.

Basically, I got this from my client.

M2ts is blu-ray and I will not even go into that.

AVI - I've always thought this is kind of old-school and that there are better ways to do it these days.

I've mostly worked with h.264 so I decided to go with m4p. But hold on a sec - isn't m4p an audio format only??

So I created a template in Compressor using the setting above for m4p. However, in Compressor - the highest bitrate it will let me choose is 2048kbps. Then how could I create a file that's 20Mbps??

1920x1080 (16:9), 29.97fps, AVC - all that is pretty clear to me.

Then we get to the second line: "(High@L4.0)(CABAC/ 4 Ref Frames)" - Can somebody please translate this to me? I have no idea what any of that stuff means.

As far as audio goes - I was able to set everything in compressor except for the "16 bits" part. I don't see an option for that. Does it even matter?

So I did a little test with the settings in Compressor that you see above and what I got was an audio file. Duh. I changed the extension of the file to .mp4 and the file now opened up in quicktime and played the video part as well. Which looked really bad because, I assume, it exported at 2,048 kbps and 1920x1080.

Help anybody?