A Bridge number is based on the numerical difference between two closely related aspects in your chart. It is the gap you need to "bridge" in order to create a more harmonious bond between the two areas.

The following Bridge number connects your Heart's Desire and Personality numbers. It suggests things you can do to help your deeper self to align more closely with your personality; the "outer" you that is apparent to others. 

With a little exaggeration, you could say that your Personality number is somewhat like your mask; it's a more superficial aspect you reveal to the world. You can imagine how much more comfortable and less inhibited the experience of life becomes when you can align your authentic self with the personality you show to the world.