Kissing is a physical act where two people press their lips together, often as a sign of affection or greeting. It can vary in style and meaning across different cultures. For example, in some places, a kiss on the cheek is a common way to say hello, while in others, a romantic kiss is a way to express love. Kissing can also have biological effects, such as the release of hormones like oxytocin, which promotes bonding and feelings of closeness. Additionally, it can serve as a form of non-verbal communication, conveying emotions that words may not fully express.