Applescript iTunes dictionary explanations

Question

I am wondering what the different color schemes mean in the following:

What does the blue C tag mean? and the purple one?

Disclaimer: absolute OSX newbie here... please be gentle ;-)

Answer 1

The blue "C" means "command". You use these like so:

tell application "iTunes" to <command> --search, stop, update, eject, etc

The purple C means "class". These represent different types of data that can be extract from iTunes, and selecting a single class shows what properties it has (the orange E). Classes (or instances of classes, really) are what's returned to you after you request information, like so:

tell application "iTunes"
   set currentSong to the current song
end tell

After running this, currentSong will contain an instance of the Song class, which you can then ask for information, like who its artist is, etc.