Proximity

The main principle of proximity is: Group related items together. (related items are seen as one cohesive group rather than a bunch of unrelated things). Proximity gives the readers an instant visual clue as to the organization and content of the page. When item are close to each other, they become one unit. 

When adjusting the proximity, you have to make some changes in the size, weight or location of items. 

The basic purpose of proximity is to organize. 

Avoid a lot of separate elements on a page. 

Don't group elements that don't belong together.