which consumes 更多 internet/data? downloading 或者 streaming?

It`s +/- same amount of data. Everything really comes down to several factors:
*are 你 going to watch the file 更多 than once? (If yes, downloading is the best option. If no, then streaming might be 更多 efficient)
*does quality of the file matter? (e.g. if 你 download file, it will be in the quality it is, while 你 can adjust quality and stream it in lower resolution, therefore using less data)
*do 你 have a lot of free 太空 for file storing? (If the 太空 on 你 computer/phone is huge, 你 can surely store downloaded files on there. But if 你 may run out of storage, better option would be to stream.)
If quality would be same, storage doesn`t matter and you`re going to watch it only once, then downloading it to your computer vs streaming(technically just downloading it temporarily in your web cache) would take up equal amount of data. :)