Physical intimacy is:

1. Physical closeness
2. Touching, especially tenderly
3. Touching intimate parts, outercourse
4. Sexual penetration

The list is logically in order of increasing degree, with each form implying the previous one, but of course, it is not necessarily in order of increasing enjoyment.

Touching may include:

• Holding hands
• Hugging: gently enclosing the arms around the trunk of each other
• Sitting or lying against each other
• Caressing: gently stroking body parts or hair with a hand
• Cuddling
• Back rub and massage
• Kissing
• Licking

Clothing versus nudity also plays a role. In particular, touching with clothing tends to be more intimate if the (combined) layer of clothing at the area of touch is thin and flexible. The layer can be reduced or eliminated even without undressing, by touching under someone's clothes.

Objects, especially hard or large ones, such as big buttons and zippers, piercings, jewellery, and objects in pockets, may somewhat obstruct intimate touching.

Sexual behavior involves physical intimacy. A personal relationship that does not involve sexual behavior, e.g. friendship, may involve physical intimacy. This varies greatly. In western culture it is often more among female than among male friends; the latter may want to avoid associations with homosexuality. In other cultures, such as Arab culture, men may hold hands with no implication of homosexuality.

A man and a woman who are friends may avoid physical intimacy to avoid associations with sexuality (for example if one or both have a relationship with someone else).

Physical closeness may also be involuntary, as in a crowded train or elevator. See also frotteurism, groping.

An intermediate form of voluntariness is when one goes to a crowded place for entertainment: a bar, disco, pop concert, street festival , etc.

A cuddle party is a party where strangers cuddle, touch, caress, and massage, subject to rules such as no nudity, no hands under clothes, no French kisses and no dry humping or other sex.

December 4 is considered International Hug Day .

See also: Public display of affection, Jealousy, Kruibeke.

Physical intimacy between a human and an animal may involve petting (caressing), hugging and playing.

Also a person, especially a child, may caress and hug a teddy bear or doll. There are also sex dolls, as a surrogate for a person.

Other kinds of intimacy are:

• emotional intimacy: telling about emotions, knowing and feeling what the other feels
• financial unity, sharing property, community-property