A stereotype is an opinion or perception one has about a person or group of people/things based on the actions or behaviors of people who are similar.
Stereotyping is a very common practice for a majority of people. Stereotyping people and things around us help to simplify our social world as it reduces the amount of thinking and processing we have to undertake when meeting a new person. We stereotype because we do not have enough time in the world to get to know every single person that we come across and so it is a lot quicker and easier to believe in the stereotypes that we have accumulated through the media and the people around us. Stereotypes can also be created due to one person or a small group of people doing something out of the ordinary which creates a stereotype of that person/small group of people and all the groups they are associated with.
For example; Muslim terrorist attacks such as the attack on the twin towers in the USA has caused many people around the world to have negative thoughts and images towards all Muslims (believers in Islam) being dangerous and involved in terrorism.
The media display stereotypes in many different ways which cause us as the audience to believe them to be accurate. Some examples of media that use stereotypes are films, TV programs and magazines. Directors use stereotypes that are common and viewers are already quite aware of in their own lives in order to simplify the amount of explaining that must be done in the TV program or film in order for the audience to understand what each character is like. For example, when the audience see's a thin cheerleader with blonde hair in the media we automatically perceive her to be not very intellectual, popular and quite ditsy. We believe that she doesn't care much about her education and is solely focused on her looks and relationships.
This example of a stereotype could be very relevant to blonde cheerleaders in our society, however it could be very inaccurate and the stereotype can cause us to have a big misconception of someone who could be the complete opposite of the stereotype often imposed on them.