Exponential time refers to a situation where the time required to solve a problem increases dramatically as the size of the problem grows. For example, if you have a task that takes 1 hour for 10 items, it might take 1,000 hours for 20 items. This rapid increase can make certain problems, like those in computer science or mathematics, very difficult to solve as they scale up. In practical terms, algorithms that run in exponential time are often impractical for large inputs. For instance, the traveling salesman problem is a classic example where finding the shortest route becomes exponentially harder as more cities are added. Understanding exponential time helps in choosing the right approach to tackle complex problems efficiently.