There are many types of museums, including art museums, natural history museums, science museums, war museums, and children's museums. Amongst the world's largest and most visited museums are the Louvre in Paris, the National Museum of China in Beijing, the Smithsonian Institution in Washington, D.C., the British Museum and National Gallery in London, the Metropolitan Museum of Art in New York City and Vatican Museums in Vatican City.
As of the 2010s, the continuing acceleration in the digitization of information, combined with the increasing capacity of digital information storage, is causing the traditional model of museums (i.e. as static bricks-and-mortar "collections of collections" of three-dimensional specimens and artifacts) to expand to include virtual exhibits and high-resolution images of their collections that patrons can peruse, study, and explore from any place with Internet. According to The World Museum Community, there are more than 55,000 museums in 202 countries.
The English "museum" comes from the Latin word, and is pluralized as "museums" (or rarely, "musea"). It is originally from the Ancient Greek Μουσεῖον (Mouseion), which denotes a place or temple dedicated to the Muses (the patron divinities in Greek mythology of the arts), and hence a building set apart for study and the arts, especially the Musaeum (institute) for philosophy and research at Alexandria by Ptolemy I Soter about 280 BC.
The purpose of modern museums is to collect, preserve, interpret, and display items of artistic, cultural, or scientific significance for the education of the public. From a visitor or community perspective, the purpose can also depend on one's point of view. A trip to a local history museum or large city art museum can be an entertaining and enlightening way to spend the day. To city leaders, a healthy museum community can be seen as a gauge of the economic health of a city, and a way to increase the sophistication of its inhabitants. To a museum professional, a museum might be seen as a way to educate the public about the museum's mission, such as civil rights or environmentalism. Museums are, above all, storehouses of knowledge. In 1829, James Smithson's bequest, that would fund the Smithsonian Institution, stated he wanted to establish an institution "for the increase and diffusion of knowledge."
Museums of natural history in the late 19th century exemplified the Victorian desire for consumption and for order. Gathering all examples of each classification of a field of knowledge for research and for display was the purpose. As American colleges grew in the 19th century, they developed their own natural history collections for the use of their students. By the last quarter of the 19th century, the scientific research in the universities was shifting toward biological research on a cellular level, and cutting edge research moved from museums to university laboratories. While many large museums, such as the Smithsonian Institution, are still respected as research centers, research is no longer a main purpose of most museums. While there is an ongoing debate about the purposes of interpretation of a museum's collection, there has been a consistent mission to protect and preserve artifacts for future generations. Much care, expertise, and expense is invested in preservation efforts to retard decomposition in aging documents, artifacts, artworks, and buildings. All museums display objects that are important to a culture. As historian Steven Conn writes, "To see the thing itself, with one's own eyes and in a public place, surrounded by other people having some version of the same experience can be enchanting."