What are the key differences between on-road and off-road bicycles, and how do these differences impact their performance and suitability for different types of terrain?

On-road bicycles are designed for smooth surfaces like pavement, with narrow tires and lightweight frames for speed and efficiency. Off-road bicycles, or mountain bikes, have wider tires, suspension systems, and durable frames for rough terrain. These differences impact performance by affecting speed, handling, and comfort. On-road bikes are better for commuting and road cycling, while off-road bikes are suited for trails and Mountain Biking.