A design pattern library offers tried-and-tested solutions to common design problems. It covers not just looks but also functionality and user interactions.

Let's say you're designing a website or an app. You might encounter familiar challenges:

• How to show lots of information without overwhelming users?
• How to guide users to complete a task like signing up?

That's where the pattern library comes in, offering proven “recipes” to solve these problems, like drop-down menus, carousels, or clean forms.

A pattern library makes designing faster and smoother. No need to reinvent the wheel each time you meet a common problem — pick the best solution from your library. It's a powerful tool for making better, more consistent designs more quickly.

Don't confuse a design pattern library with a component library. The latter contains all the individual, standardized pieces (or components) like inputs, buttons, shadows, and links that you might need to create a design. On the other hand, a design pattern, such as a registration form, uses these components to provide a standard solution to a common design problem. So, when you're creating a registration form (a pattern), you'll use components from your component library.