Web design at it's core should be about expressing as much as possible in the most minimal way imaginable. Today's web is mostly centered around mobile devices fetching data at 3g speeds or worse. What this means is that websites and web apps must load as quickly as possible. People are impatient and would not waste time on your site if it doesn't load fast. This is why when I design websites and web apps I strip the content and align it to the user interface.
If you're updating a website or web app you're going to start by stripping off it's content. Your goal should be to reduce the content by 50% while retaining the message of the content. As you trim the fat the site's message becomes clearer and it's form is left minimal, elegantly presented with up to date UI/UX patterns.
This is why design is freeing up space. The concept of design is to take an idea, a message, or slogan, anything you can think of and create a brand around it. The message, idea becomes a logo that can will represent all the words around the idea. The words themselves becomes the site's content. With the brand and the content, objects begin to form. The objects will be whatever your app is, whatever the idea is behind the brand will be the software or service.
I'll say it again, design is freeing up space.