Once the program tells you the name of the song, it offers you the possibility to download it, read the lyrics and learn a bit more about it.
Audiggle is very easy o use. You only have to play the audio you want to identify (e.g. a video on Youtube) and press the 'search' button.
It will take just a few seconds to have the answer.
From now on, you'll always know the name of those songs you like, no matter where you listen to them.