Before providing any principles of a great product design, we need to define what actually they mean. So, let’s define what a principle and product design represent separately.
The word “principle” means “a basic idea or rule that explains or controls how something happens or works”.
Product design is a process of creating a product that aims at solving the user’s problems, needs and providing them with an effective solution.
So taking these two things into account, we may assume that product design principles are a set of rules that help teams create applications in the most efficient way possible.