Theoretical and practical are two terms that are often used to describe different aspects of a concept or idea. The main difference between them is that theoretical refers to ideas or concepts that are based on theory or principles, whereas practical refers to things that are based on actual experience, application or implementation.
In other words, theoretical knowledge is based on abstract concepts and principles, whereas practical knowledge is based on real-world experience and application.
For example, if you were studying physics, you would learn about the theoretical principles of how gravity works. However, if you were actually designing and building a bridge, you would need practical knowledge of how to apply those principles to create a safe and structurally sound structure.