Socialization is the process of preparing children to become adult members of society. Some of this is done intentionally but a significant amount of socialization occurs unintentionally as children discover which behaviors are appropriate or inappropriate by observation and experimentation.
Parents socialize children both intentionally and unintentionally. When a parent insists that a child say "please" or "thank you" or teaches a child table manners, that is intentional socialization. The parent's own behavior, however, socializes the child unintentionally. For example, if parents put away electronic devices, dine together, and converse and pay attention to each other during dinner, that teaches the children one sort of behavior, whereas if parents spend dinnertime on the phone or watching TV, and seem more concerned with electronic devices than with their families, that teaches children a very different sort of behavior.
Schools also contain examples of intentional and intentional socialization. Schools explicitly teach both various subjects and also proper behavior such as standing in line, not yelling, and taking turns. Peer group interactions, however, are a form of unintentional socialization in which students learn the rules of their particular cohort. Children may learn gender norms, for example, from observing what is admired among their peers or from popular media in a form of unintentional socialization.