Designing systems that work for the users.
User Centered Design
User Centered Design is the idea that a system's interface is for the user. When developers make design decisions accordion to their own assumptions, they easily miss things that from the user's perspective makes it hard to use the system.
If you're making a business website, the user is the customer. What are they looking for on the website? Make sure the hours and location are prominent, and the offerings are presented in an enticing way. How will you give them what they want? What are the steps that need to happen? Understanding this process is the key to streamlining it. Find people who are representative of the audience and find out what they see when shown the UI and asked to perform different tasks.
UI Design
Clear interface labels and layout.
Storyboarding
A technique for modeling user's experience.
User Stories
A description of a user interaction.