There is a big difference between UI/UX design and web design. Web design is all about the look and feel of a website, while UI/UX design is all about making the user experience as smooth and intuitive as possible.
A good UI/UX designer will take into account everything from the layout of the page to the color scheme to the way the buttons work and shall map the user journeys of all the anticipated visitors to the digital product so that all the users shall be able to find the right information at the right place with minimum clicks. They ensure that users can find what they need quickly and easily and that they enjoy using the site.