In this video Rhona Nasson uses a toy and a key word to mark the desired behaviour.
The advantage of using a clicker, is that trainer is able to reward a desired behaviour rapidly and this increases the chance that the dog will associate the click with something nice happening. (usually food).
The click and reward event is repeated until the dog has made the association. You may be surprised how quickly this happens. Once established the response to the ‘click’ can be maintained and strengthened via variable or intermittent reinforcement, ie food does not follow after every click.
Clicker training is a wonderful way to train dogs, letting the dogs use their brains to offer you the behaviour that you are looking for.
There really isn’t a limit to what you can train your dog to do.