What is a bridge clothing line?

A bridge clothing line is the price point right before luxury clothing. So for example Dolce and Gabbana would be the luxury line, which would feature clothing that ranged in prices from say 800$ to maybe 30,000$ depending on the item, whereas with the bridge line, which would be D&G your clothing may range from 100$ to 600$ (the price ranges aren't correct, just used to illustrate the point).