Deliver video over the internet

Different means:

1. Streaming : 
   - delivered streaming server.
   - data rate of encoded file must be smaller than the bandwidth capacity in order to provide smooth playback.
   - video can be cache-less, so more secure in terms of copyright protection.
2. Progressive Download:
   - delivered via HTTP web server
   - QuickTime Player require special requirement, video must be encoded with Fast Start option selected; H.264 files distributed to Flash Player must have MOOV atom,etc.
3. Adaptive Streaming:
   - video quality / data rate varies according to the available bandwidth. Higher quality, higher data rate for high speed connection.
   There are multiple adaptive streaming alternatives today, including Adobe’s Dynamic Streaming, Apple’s HTTP Live Streaming and Microsoft’s Smooth Streaming
   

source: http://www.onlinevideo.net/2011/05/streaming-vs-progressive-download-vs-adaptive-streaming/