Here is a quick intro to a very important concept. What I have below is a portion directly from Wikipedia. I really like the intro from Wikipedia:
Personal boundaries are guidelines, rules or limits that a person creates to identify for him- or herself what are reasonable, safe and permissible ways for other people to behave around him or her and how he or she will respond when someone steps outside those limits.
Types of personal boundaries
‘Personal boundaries include physical, mental, and spiritual boundaries’ – (for physical boundaries see personal space and proxemics). ‘Mental boundaries pertain to beliefs, emotion, and intuition…Spiritual boundaries pertain to self-esteem [&] sense of identity’. Together they constitute “psychological boundaries”.
According to Nina Brown, there are four types of psychological boundary:
For a much more in depth explanation check out Dr. Paul and David DeAngelo. Although a few years old, their program called "Deep Inner Game" is outstanding in the area of Personal Boundary...
For my take on Personal Boundary as it pertains to women, read my blog on Strength of Frame.