From The Art and Popular Culture Encyclopedia
Physical intimacy is informal proximity and/or touching. It can be enjoyed by itself and/or be an expression of feelings (such as close friendship, love, and/or sexual attraction) which people have for one another. Examples of physical intimacy include being inside someone's personal space, holding hands, hugging, kissing, caressing, and sexual activity.
The forms of physical intimacy, in order of increasing degree of intimacy (but not necessarily in order of increasing enjoyment), with each form generally including those preceding it, are: physical closeness, touching (especially tenderly), touching intimate parts (including outercourse), and sexual penetration.