Ethnocentrism is when a person tries to judge the culture of other people from the point of view of their own culture. Ethnocentrism can look at things like language, custom, religion and behavior.
An ethnocentric person will use their own culture as the basis for judging other cultures. They see their own culture as the best and believe other cultures should change to be more like theirs.
The term was first used by sociologist William G Sumner. He defined it as “the technical name for the view of things in which one's own group is the center of everything, and all others are scaled and rated with reference to it”. (PS this is more exclusive word for "racist")
All people tend to use the values of the culture we were born in. One of the main goals of anthropology is to not use ethnocentric ideas. Anthropologists try to see other cultures from the point of view of a person from that culture . This is also known as cultural relativism. It is the idea that goes against the idea that some things are always the same in every human culture (human universals). Cultural relativism says that all human action is relative to the culture where the action happens. Anthropologists know that they have to not use the standards of their own culture if they want to understand another society correctly.
Sumner, W.G. Folkways: a study of the sociological importance of usages,manners, customs, mores, and morals (Boston: Ginn and Co., 1906)