There are 2 types of lessons:
Developmental - If you want to learn a swing or change it for the better, it's important to realize that it's a gradual process. We'll work together in a step by step process, giving you time to practice in between. Your mind may know what to do, but it takes training for the body to be able to do it. If you are a beginner, I would recommend a series as well as a playing lesson.
Maintenance - You may have the basics down, but that doesn't mean you won't get off track once in a while. The most elite golfers struggle at times and are quick to go back to their teacher when it falls apart. The swing is like a car —you can build it properly and it will run well, but it will always need some maintenance down the road.