A museum is a “permanent institution in the service of society and of its development, open to the public, which acquires, conserves, researches, communicates and exhibits the tangible and intangible heritage of humanity and its environment, for the purposes of education, study, and enjoyment”, as defined by the International Council of Museums.^[1] The UK Museums Association definition (adopted 1998)^] is:

Museums collect and care for objects of scientific, artistic, or historical importance and make them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities throughout the world and more local ones exist in smaller cities, towns and even the countryside. Many museums offer programs and activities for a range of audiences, including adults, children, and families, as well as those for more specific professions. Programs for the public may consist of lectures or tutorials by the museum faculty or field experts, films, musical or dance performances, and technology demonstrations. Many times, museums concentrate on the host region's culture. Although most museums do not allow physical contact with the associated artifacts, there are some that are interactive and encourage a more hands-on approach. Modern trends in museology have broadened the range of subject matter and introduced many interactive exhibits, which give the public the opportunity to make choices and engage in activities that may vary the experience from person to person. With the advent of the internet, there are growing numbers of virtual exhibits, i.e. web versions of exhibits showing images and playing recorded sound.

Museums are usually open to the general public, sometimes charging an admission fee. Some museums are publicly funded and have free entrance, either permanently or on special days, e.g. once per week or year.

Museums are usually not run for the purpose of making a profit, unlike private galleries which more often engage in the sale of objects. There are governmental museums, non-governmental or non-profit museums, and privately owned or family museums. Museums can be a reputable and generally trusted source of information about cultures and history.

There are many types of museums, from very large collections in major cities, covering many of the categories below, to very small museums covering either a particular location in a general way, or a particular subject, such an individual notable person. Categories include: fine arts, applied arts, craft, archaeology, anthropology and ethnology, history, cultural history, military history, science, technology, children's museums, natural history, numismatics, botanical and zoological gardens and philately. Within these categories many museums specialize further, e.g. museums of modern art, local history, aviation history, agriculture or geology. A museum normally houses a core collection of important selected objects in its field. Objects are formally accessioned by being registered in the museum's collection with an artifact number and details recorded about their provenance. The persons in charge of the collection and of the exhibits are known as curators.

An Art museum, also known as an art gallery, is a space for the exhibition of art, usually in the form of art objects from the visual arts, primarily paintings, illustrations, and sculpture. Collections of drawings and old master prints are often not displayed on the walls, but kept in a print room. There may be collections of applied art, including ceramics, metalwork, furniture, artist's books and other types of object. Video Art is often screened.

The first publicly owned museum in Europe was the Amerbach-Cabinet in Basel, originally a private collection sold to the city in 1661 and public since 1671 (now Kunstmuseum Basel).^[8] The Uffizi Gallery in Florence was initially conceived as a palace for the offices of Florentian magistrates (hence the name), it later evolved into a display place for many of the paintings and sculpture collected by the Medici family or commissioned by them. After the house of Medici was extinguished, the art treasures remained in Florence, forming one of the first modern museums. The gallery had been open to visitors by request since the sixteenth century, and in 1765 it was officially opened to the public. Another early public museum was The British Museum in London, which opened to the public in 1759.^[9] It was a "universal museum" with very varied collections covering art, applied art, archaeology, anthropology, history, and science, and a library. The science collections, library, paintings and modern sculpture have since been found separate homes, leaving history, archaeology, non-European and pre-Renaissance art, and prints and drawings.^{[citation needed]}

The specialised art museum is considered a fairly modern invention, the first being the Hermitage in Saint Petersburg which was established in 1764.^{[citation needed]}

The Louvre in Paris, France was established in 1793, soon after the French Revolution when the royal treasures were declared for the people.^[10] The Czartoryski Museum in Kraków was established in 1796 by Princess Izabela Czartoryska.^[11] This showed the beginnings of removing art collections from the private domain of aristocracy and the wealthy into the public sphere, where they were seen as sites for educating the masses in taste and cultural refinement

History museums cover the knowledge of history and its relevance to the present and future. Some cover specialized curatorial aspects of history or a particular locality; others are more general. Such museums contain a wide range of objects, including documents, artifacts of all kinds, art, archaeological objects. Antiquities museums specialize in more archaeological findings.

A common type of history museum is a historic house. A historic house may be a building of special architectural interest, the birthplace or home of a famous person, or a house with an interesting history. Historic sites can also become museums, particularly those that mark public crimes, such as Tuol Sleng or Robben Island. Another type of history museum is a living museum. A living museum is where people recreate a time period to the fullest extent, including buildings, clothes and language. It is similar to historical reenactment.

Science museums and technology centers revolve around scientific achievements, and marvels and their history. To explain complicated inventions, a combination of demonstrations, interactive programs and thought-provoking media are used. Some museums may have exhibits on topics such as computers, aviation, railway museums, physics, astronomy, and the animal kingdom

Science museums, in particular, may consist of planetaria, or large theatre usually built around a dome. Museums may have IMAX feature films, which may provide 3-D viewing or higher quality picture. As a result, IMAX content provides a more immersive experience for people of all ages.

Also new virtual museums, known as Net Museums, have recently been created. These are usually web sites belonging to real museums and containing photo galleries of items found in those real museums. This new presentation is very useful for people living far away who wish to see the contents of these museums.

specialized museums

A number of different museums exist to demonstrate a variety of topics. Music museums may celebrate the life and work of composers or musicians, such as the Rock and Roll Hall of Fame in Cleveland, Ohio. Other music museums include live music recitals such as the Handel House Museum in London. In Glendale, AZ, USA The Bead Museum http://www.beadmuseumaz.org/ fosters the appreciation and understanding of the global historical, cultural and artistic significance of beads and related artifacts. The permanent collection includes beads from around the globe including a 15,000 year old bead. Temporary exhibits are also available.

Museums targeted for the youth, such as children's museums or toy museums in many parts of the world, often exhibit interactive and educational material on a wide array of topics, for example Museum of Toys and Automata. The Baseball Hall of Fame and Museum is an institution of the sports category. The Corning Museum of Glass is devoted to the art, history, and science of glass. The National Museum of Crime & Punishment explores the science of solving crimes.