MediaLocator and URL
URL - Uniform Resource Locator
MediaLocator  locates a media source
MediaLocator and URL can be constructed
using LocatorString.
Examples for Locator String
Ø file://ring.wav
Ø javasound://44100, vfw://0
Ø rtp://144.16.251.120:9000/audio/1
Ø http:// www.mywebsite.com/clip.mov
Ø rtsp:// host:port/mediafile
Unlike an URL or a MediaLocator  a DataSource
provides control over media access.