Quicktime
Quicktime is the video format devised through and used through Apple and can be utilized at varying quality and file sizes. This is quite broadly used and has affected the design of the MPEG formats.
Real Video
It is a streaming video format employed for distributing video in actual-time over the internet. Along with streaming video, you do not need to download the complete file before starting to watch it. Rather the viewer will download the first section of the video whereas the remainder downloads in the background.