Display bounds vs. Encoded bounds

This will seem elementary to some of you, and that is precisely why I am asking here,.. I hope you can help.

I am wondering why when I export a NTSC DV (720x480) from FCP to Compressor the Inspector tells me that the Encoded bounds say it is 720x480 but the Display bounds say 640x480? What is display bounds, and/or does this effect my project, or is it normal?

As a side note: When I export widescreen to Compressor, it has Encoded as 720x480 and Display as 853x480 (which I have come to understand as DV 16x9 recording resolution).

I guess my question is what is display bound vs. encoded bound

Thanks.