Here are the four distance measures most people use in communicating. For some people, there may be a variance -- often dictated by the space available in the location of the communication. But in general, here's what we tend to expect in communication:
Public space is often the largest amount of space between you and the speaker. Think of an auditorium where someone is making a speech or lecture or even bigger -- this is public space. Usually, 12-25 feet. And often determined by the size of the room as well as what is going on there.
When we think of social space (4-12 feet distance to the speaker), this is generally the distance between you and a speaker in a group, or possibly between you and a sales clerk in a store or customer at work. You can hear easily and this tends to be comfortable, but you’re not so close usually that you can touch the person with whom you are communicating.
Personal space (1-4 feet distance) is often described as the distance you might keep if you were shaking someone’s hand. This is usually characterized as the way you talk to family and friends.
Intimate space is for those you are closest with – less than a foot away and perhaps touching. A child you are comforting, a romantic partner, someone with whom you feel very comfortable – these scenarios tend to fall into this category.
In about 250 Words discuss these situations.