Default Anyone want to explain spare parts app to me

I just want to understand what all the mess it in the battery history? why does it show some stuff with a blue line then pink at the end? and why will it show some of the lines going all the way till the end and then same are only half or a quarter filled? whats that mean that the app was running the entire time or what? Also what is partial wake usage? I wish i was rooted and could screen shoot but i got some camera pics