Road Bikes: They are lighter and designed for speed and performance, comfort is less important. For racing, touring and long rides on bike paths and roads. Narrow wheels and tires are fragile and require more maintenance.
12 speed: good to go just about everywhere except very steep hills. The range of different ratios are more than enough for most people. There are 2 front chain rings and 6 rear gears. - Derailleur: TBD
Tires 700 x 23c: very narrow tires, slick, for racing on asphalt.