This advanced obedience level will teach you how to train behaviors in the presence of distractions, with duration, and from a distance. (charlestonanimalsociety.org)
Once this step is complete, you are ready to start training behaviors with the clicker! (wooftopia.ca)
The clicker itself is simply a little toy - like device that is used in the initial stages of training any behavior. (clickerlessons.com)