1) Physical comfort zone 
Personal space is the region surrounding a person which they regard as psychologically theirs. Most people value their personal space and feel discomfort, anger, or anxiety when their personal space is encroached. Permitting a person to enter personal space and entering somebody else`s personal space are indicators of perception of those people`.....
the surrounding area to which an individual makes some claim to privacy
(from the article `social behaviour in animals`) Colonies-4 are known among other arthropods. Tube-dwelling amphipods form colonies but chase each other and avoid getting too close. They show the ...
The physical space individuals maintain between themselves and others; it may vary between intimate distance for close relationships, social distance for formal encounters and public distance when confronted by an audience.
Invisible boundaries surrounding the individual's body which are maintained in relation to others. ... (12 Dec 1998) ... 
Type: Term Definitions: 1. a term used in the behavioral sciences to denote the physical area immediately surrounding a person who is in proximity to one or more others, whether known or unknown; serves as a body buffer zone in such interpersonal transactions. Measure of space determined as appropriate varies widely among ethnic groups and cultures...
The area immediately around one’s body that one can claim as one’s own.