I'm aware of what a stream is. Are you familiar with the Netflix, some may call it "rental" model? Apparently they let you "borrow" movies, I'm told for days at a time. Apparently you have to have a continuous internet connection to "stream" which kinda sucks when you have to move from one place to another.
"Stream" is a euphemism for "download you are not allowed to keep".
Expect to keep seeing the word "stream" for a while.