Heart and Soul!

I have listened to a bunch of musics with heart and soul, lately. One example is When you're gone by Avril Lavigne, which is down the explanation.

So, Heart and soul means like completely, entirely. People usually use to give one's heart and soul, for example:

She loved him with her heart and soul.

The lyric of the music says "All I ever wanted was for you to know, everything I do I give my heart and soul". It means basically she is dedicated on what she does.

Get it?!