Streaming video is video that is stored remotely and delivered over the internet rather than sent, downloaded and stored on your computer or on a dvd. The difference in the quality is in the fact that streaming video is delivered a few seconds at a time rather than continuously the way a stored video is. The advantage is that it can be delivered widely.
Most streaming video has restricted access, so you need to go through an institution like Temple or the public library to get to them if you do not want to buy or rent them for yourself. The big consumer services such as Netflix, Amazon, or Hulu do not offer licensing to the educational market.