In modern economics many well-known and popular categories still remain unclear or even out-of-date. Especially two microeconomics concepts connected with market analysis need to be refreshed and redefined: luxury goods and necessity goods. In the contemporary world the understanding of luxury and necessity is changing because of many reasons, for example: growing income level, processes of democratization of luxury and poverty, globalization of markets, mass-production and wider access to information. Therefore deeper studies seem to be interesting and necessary. In the paper, there are indicated these elements of modern economic theory where these two types of goods are discussed and described and then the evolution in understanding of luxury goods and necessity goods concepts in economics is shown. Also, the backgrounds of concepts creation are briefly described as well as the subsequent changes in their understanding and then the present meaning of luxury and necessity is presented. The main hypothesis states that in economics only the understanding of luxury goods has been changed while the perceiving of necessity goods remains unchanged.