Whitespace is the empty or “negative” space between elements on a page. Those elements can be anything from paragraphs and bullet lists to images and advertisements. Utilization of whitespace in webpage layout is underrated and all too commonly underused. Whitespace can benefit visitors by preventing the feeling of being “overwhelmed” or being annoyed by too much "going on." Whitespace can also be used to create emphasis; focusing visitors on the most important information.
Look at the difference between the following website screenshots:

Figure 1

Figure 2
Do you “feel” the difference between the two designs? What is the general feeling you get from figure 1 compared to figure 2? Figure 1 has an open and airy design creating a sense of sophistication and calm while Figure 2 exudes frustration and stress. Which would you rather your audience feel?
When managing the content on your website, don’t be afraid to add some space between elements. It may be subtle but can really improve the visual effectiveness of your content.