On the other hand, some people argue that museums should focus on education. The aim of any exhibition should be to teach visitors something that they did not previously know. Usually this means that the history behind the museum’s exhibits needs to be explained, and this can be done in various ways. Some museums employ professional guides to talk to their visitors, while other museums offer headsets so that visitors can listen to detailed commentary about the exhibition. In this way, museums can play an important role in teaching people about history, culture, science and many other aspects of life.