Each letter in the personality type code - I, S, F, and J - describes a preference for a way of thinking or behaving. There are eight styles and you use all of them, but ISFJs prefer:
Introversion (thinking things through) more than Extraversion (interacting with people)
Sensing (perceiving tangible facts) more than iNtuition (perceiving new possibilities)
Feeling (making decisions using subjective values) more than Thinking (making decisions using objective logic)
Judgement (an organised lifestyle) more than Perception (a flexible lifestyle)
If your closest personality type is ISFJ then you are interested in knowledge and experience, particularly in relation to family, friends and colleagues. You are a quiet, serious observer of people, listening intently and getting to know a great deal about them. You pay attention to their emotions and feelings, and are keenly aware of the state of relationships between them and you take your responsibilities to them very seriously.
Stereotypes and Individuality
The original author of personality type theory - Carl Gustav Jung - said that everyone is individual and unique. The personality types are not strict classifications, but stereotypes that are akin to landmarks on a map. Just as a few landmarks can help you find many unique locations, so too the personality stereotypes can help you understand your unique personality.