Museums are dedicated to helping people understand and appreciate the history of civilizations, and the record of humanity’s artistic, scientific, and technological achievements. Museums collect objects of scientific, aesthetic, or historical importance; care for them; and study, interpret, and exhibit them for the purposes of public education and the advancement of knowledge. There are museums in almost every major city in the world and in many smaller communities as well.

The major types of museums are art, history, natural history, and science. In certain museums, these disciplines may be combined. Within these categories there are also many specialized museums emphasizing particular topics or types of collections, such as museums of local history, music, the cultural heritage of native peoples, or maritime history.

In the United States, there are approximately 8,300 museums of all types, with history museums being the most common type. Canada has about 1,400 museums. In the late 1990s there were, annually, more than 800 million visits to U.S. museums and more than 25 million visits to Canadian museums.

Online exhibitions and virtual museums extend a museum beyond its physical walls and invite virtual visitors to explore images and text at their own pace. These exhibitions range from digital images of a museum’s works to three-dimensional, interactive tours of a museum’s galleries with audio and video.