Understanding Audacity graphs

[kinega]

Can anybody offer any advice on understanding what the graphs show in Audacity. Have been reading the online help & general google searches but can't find anything to explain it to me in simple terms!
I would just like a simple explanation of what the various graphs mean & practical examples of what it all means.
Many thanks

[kinega]

answering my own question, some useful info here:
http://www.computeraudiophile.com/f14-music-analysis-objective-and-subjective/music-analysis-objective-and-subjective-9354/