Streaming/Progressive Video

What is the difference?
 
I tried looking, but perhaps I didn't search "hard" enough.

Progressive downloads the video, so you can't jump around in the timeline until everything is loaded. 
 
Streaming lets you jump around all you want. 

Progressive when the bar loads you can go anywhere in the video.
Streaming is when you go to any area, it has to load.

But let's be honest: there's no reason to jump around most GB videos because you might miss some lols.

progressive downloads the file and caches it to your hard drive. 

I was wondering the same thing, and now I've learned something.

Streaming starts with a persistent connection to a streaming server - it utilizes a buffer (typically as large as possible until the entire video is downloaded) and doesn't empty it until you're done viewing. It also allows you to select points-in-time of the video. Hence, you can jump around, fast forward, etc. 
 
Progressive is essentially the old school UDP dump to a client. It's just a small buffer that hurls packets at the client and relies on the client to sort it out.