White space is a page layout term and refers to the areas of a web page that have no text or graphics on them.

Put simply, white space, is the space between stuff.

A typical web page will be made up of headers, text, photographs, videos etc. How much space is left between each of these elements is an important aesthetic decision.

White space isn't worthless or empty. It makes a page readable and useable. Clients often include the word "clean" in a brief, saying that they want their web site to be clean. In many ways, this is achieved by good use of white space.

Where space is at a premium, e.g. where it is related to advertising, a web page can become cluttered.

Of course, the background colour of a web page can be changed or textured, so white space isn't always white, but in this case, the term would still be used.