"Culture shock" is a term used for a sense of disorientation and confusion that most people experience when they arrive in another country or when returning to their home country after an extended period in a foreign country. New visitors to a different culture have left everything they consider "natural" and familiar and are expected to function in a new country right away. Culture shock is a normal and temporary part of the process of adapting to a new environment, and there is no reason to be overly concerned.
Getting acquainted with social and cultural differences is a very important process because it will help you build relationships with Americans. Below you will find some common American customs you are likely to encounter.