The short answer: A design is a solution to a problem.
Design is about solving problems.
Simple enough, but how can we use this information? How can we make this a tool to improve future designs? The problem is that now that we have defined design, we also need to define problems in order to really get to the bottom of design and really see how we can use it.
Problems arise when there are two opposing wills, or forces. So, a problem is a flow, movement, or dynamic that has been stopped by an opposite. It can be visualized as a wall or a barrier.
Problems are solved in one of two ways: force or by understanding.
Force can be effective but it is seldom clean or even acceptable as a solution. War and fighting is a good example that may work, but we don’t want it. A hammer can crack a nut but it can also do a lot more damage besides.
Understanding, on the other hand, is the clever, clean solution. With understanding we can design a solution. A nut cracker will uncover the nut without the collateral damage.
So, the best solver of problems, for our purposes, is understanding.
The trick now is to understand Understanding so we can truly make use of design. How deep does this rabbit hole go? Not much further.
Understanding is made up of three parts. These are Affinity, Reality and Communication. Together they form the ARC triangle*.