Touring bikes are designed for traveling over long distances. They feature large displacement engines, big windscreens connected to protective fairings(the shell covering the exterior of a motorcycle), and handlebars that encourage a relaxed sitting position. Most touring bikes have a significant amount of luggage as well.
You may also hear touring bikes called baggers, full dressers, full dress tourers, or dresser. Most of these names were originally for specific motorcycle types with full saddlebags such as Harley Davidsons but they are now regularly used for any type of touring motorcycle.