There are many ways in which a society can socialize a child. One way to categorize the things society can do is by splitting them into formal and informal types of socialization.
Formal socialization occurs when we are specifically trying to teach our children how to act and what to believe. This happens at school when we tell children that democracy is the best form of government and that capitalism is the best economic system or that it is important to be patriotic. It happens at church when we tell (depending on the church) girls that they have a different role in society than men do. It happens with parents when they are specifically telling their children what they expect. This would be, for example, when they tell children that they expect them to try hard, that they expect them to want to be the best, or that they should focus on making themselves happy. All of these are instances when someone is specifically telling children what is expected of them.
Informal socialization occurs when we do not explicitly tell children what to believe or how to act. In this case, we model our expectations or show those expectations through our actions. This could happen when a father does not help with the housework, showing his children that our society does not expect men to do this. It could happen when characters on a TV show make fun of a fat character, sending the message that it is bad to be fat. It could happen when teachers congratulate athletes in class on the day after they win a game but fail to compliment band members on a good performance. All of these are inexplicit ways in which we tell children what we expect of them.