Dream control is the ability to do things in a dream, many of which are not possible in real life, and thus manipulate the dream away from its natural course. Dream control is a typical feature of high-level lucid dreams, and is usually seen as highly desirable.
Often it is hard to remain in a dream while doing things that are impossible in reality; for example, someone trying to fly might suddenly fear falling and wake up. However, doing some impossible things could actually help with remaining in lucidity by reminding the dreamer that they are doing things that cannot be done in the waking world, thus accentuating that they must be dreaming.