Retirement tax questions

I dont have good knowledge on this terminology.

 

Please could you explain the difference between "Canadian RRSP distribution" and "Contributing to Canadian RRSP"

 

I am Canadian citizen and working in US for the past 2 years+. I have more than 20K as RRSP room.
Wondering whether I can contribute to Canadian RRSP with USA income and during the search found your post. hence replying here.