Consistency in UI design is about making sure that UI elements look and behave the same way. As users start navigating your website or app, they start noticing how the UI works. From their experience, they assume that other pages work similarly. Proving these assumptions right creates a sense of control, familiarity, and reliability.

Here's a list of some benefits that UI design consistency brings to the table:

• It increases usability. Users know what to expect if your website or app behaves predictably.
• It eliminates confusion. Visual consistency helps create a logical structure and prioritize content. 
• It evokes an emotional response. Being confident that they know how to navigate your product evokes a positive emotional response. In turn, this results in a pleasant user experience.

One of the best ways to maintain consistency is to create a design system that introduces a shared set of principles and rules to build components.