Everyone is born free, loved, creative and fully self expressed. However, as we grow up we lose parts of ourselves, hide parts of ourselves and are impacted by events that happen - these things later evolve into issues in our adult life.
The idea of inner child work is that if you make an effort to contact, listen to and communicate with, and nurture your inner child within. In doing this work you can often find and heal the roots of your issues as an adult.