Consistency

Building and maintaining a consistent experience in your designs, products, and systems can have great consequences for your customers and their experience. The experience of your product should be cohesive, with a continuation from one element to the next like the way a book is structured. Every visual element cues the audience that you’re still in the same story, moving from chapter to chapter. Keeping colors, fonts, and alignment consistent helps your audience focus on the plot.

however, Consistency is often broken. It is more important to understand customer needs and solve problems than to maintain a consistent product. If you only pay attention to a rigid system, you may not be able to solve the problem. It's balance.