A museum is a not-for-profit institution that collects, preserves, and exhibits art. From the Louvre to the Met, learn how museums shape what art survives.
On August 24, 2022, the International Council of Museums (ICOM) approved a new definition of "museum" at its Extraordinary General Assembly in Prague. The previous definition, adopted in 2007, had described a museum as "a non-profit, permanent institution in the service of society and 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." The 2022 revision replaced that text with something more expansive. The new definition reads: "A museum is a not-for-profit, permanent institution in the service of society that researches, collects, conserves, interprets and exhibits tangible and intangible heritage. Open to the public, accessible and inclusive, museums foster diversity and sustainability. They operate and communicate ethically, professionally and with the participation of communities, offering varied experiences for education, enjoyment, reflection and knowledge sharing." The change took four years, multiple drafts, and heated debate among ICOM's 40,000-plus members across 138 countries. The argument was not about whether museums should collect and exhibit. It was about whether museums should be required to foster diversity, operate ethically, and include communities in their decision-making. The fact that this was controversial tells you a great deal about what museums are and what they are struggling to become.
A museum is a permanent, not-for-profit institution that collects, preserves, researches, interprets, and exhibits art and other cultural heritage for the public. Unlike a commercial gallery, a museum does not sell the work it holds. Unlike a Kunsthalle, a museum maintains a permanent collection. The museum's defining characteristic is that it holds objects in trust for the public, preserving them for future generations and making them accessible for study, education, and enjoyment. The Association of Art Museum Directors (AAMD), in its Professional Practices document, defines an art museum as "a permanent, not-for-profit institution, essentially educational and humanistic in purpose, that studies and cares for works of art and on some regular schedule exhibits and interprets them to the public."
This entry covers what a museum is, how museums developed historically, how they function in the contemporary art world, and what the 2026 institutional landscape looks like.
A museum's core functions are collecting, conservation, research, interpretation, and exhibition. Collecting involves acquiring works through purchase, gift, bequest, or long-term loan. Each acquisition is governed by a collections management policy that defines what the museum collects, how it evaluates potential acquisitions, and what criteria it uses to accept or reject works. Conservation involves preserving the physical condition of the collection through climate-controlled storage, regular condition assessments, and restoration treatments. Research involves studying the collection to produce scholarship, in the form of catalog entries, exhibition catalogs, and academic publications. Interpretation involves making the collection intelligible to the public through labels, wall texts, audio guides, educational programs, and digital resources. Exhibition involves displaying the collection, either through permanent collection installations or temporary exhibitions drawn from the museum's holdings and loans.
The governance structure of a museum typically involves a board of trustees, a director, and a professional staff. The board holds ultimate responsibility for the institution's financial health, its collections, and its mission. The director manages the museum's operations, sets its curatorial direction, and reports to the board. The professional staff includes curators, who organize exhibitions and research the collection; conservators, who preserve and restore works; educators, who develop public programs; registrars, who manage loans and shipping; and development staff, who raise funds.
The AAMD's Professional Practices document, revised in 2023, establishes standards that member museums must follow. These include clear, written collections management policies with acquisition and deaccession principles. Deaccessioning, the process of permanently removing a work from the collection, is governed by strict rules: funds received from the sale of a deaccessioned work may be used only for the acquisition of new works or for direct care of existing works, not for operating expenses or capital projects. This rule exists to prevent museums from selling their collections to pay bills, a temptation that has destroyed institutions in the past.
The word "museum" comes from the Greek "mouseion," meaning a seat or shrine of the Muses. The ancient Museum of Alexandria, founded around 280 BCE, was a research institution with a library, not a public exhibition space. The modern museum, as a building that holds and displays objects for public viewing, emerged in the 18th century.
The British Museum, founded in 1753, was the first national public museum. It was created when Sir Hans Sloane bequeathed his collection of over 71,000 objects to the nation in exchange for 20,000 pounds paid to his heirs. The British Museum Act of 1753 established the institution and opened it to the public in 1759. The Louvre, which opened as a public museum on August 10, 1793, during the French Revolution, transformed the royal collection into national property. The revolutionary government declared that the Louvre would be "a great museum, open to all, where everyone can see and study the masterpieces of art." The Prado in Madrid, opened in 1819, displayed the Spanish royal collection. The Metropolitan Museum of Art in New York, founded in 1870, was conceived from the start as a civic institution, created by private citizens rather than the state, to bring art and art education to the American public.
The 19th century saw the museum become the primary institutional form for preserving and displaying art. National museums were established across Europe and the Americas, often tied to the project of constructing national identity through cultural heritage. The museum was not a neutral container. It was an ideological instrument, presenting a particular narrative about what counted as art, whose art mattered, and how art history should be told.
The 20th century brought the museum of modern art. The Museum of Modern Art in New York, founded in 1929 by Abby Aldrich Rockefeller, Lillie P. Bliss, and Mary Quinn Sullivan, was the first museum dedicated to modern and contemporary art. Its founding director, Alfred H. Barr Jr., organized the collection around the idea that modern art was a continuous historical development, not a break from the past. Barr's famous 1936 chart, showing the development of modern art from Cezanne through Cubism to Abstract Expressionism, shaped how modern art was taught and exhibited for decades. The Tate Gallery, which opened in London in 1897 as the National Gallery of British Art, became the Tate Modern in 2000, occupying the former Bankside Power Station and becoming the most visited modern art museum in the world.
The ICOM's 2022 definition revision reflected a broader shift in how museums understand their role. The new definition's emphasis on accessibility, inclusivity, diversity, sustainability, ethical operation, and community participation was not rhetorical. It was a response to decades of criticism that museums had operated as exclusionary institutions, preserving the cultural heritage of dominant groups while marginalizing or looting the heritage of others.
The ICOM Code of Ethics for Museums, revised in May 2026, codified these principles. The revised code states that museums should "involve community members, including Indigenous Peoples, in decisions about their heritage and creative expressions, collaborating with them and respecting their right to identify, preserve, and interpret their tangible, intangible, and digital heritage." The code requires museums to seek "free, prior, and informed consent" from communities whose heritage is held in museum collections, to acknowledge their contributions, and to provide equitable compensation. This is a significant departure from the 19th-century model, in which museums collected whatever they could acquire through colonial networks, military conquest, or commercial exploitation.
The question of repatriation, the return of cultural property to its country or community of origin, has become one of the most pressing issues facing museums. The Benin Bronzes, looted by British forces in 1897 from the Kingdom of Benin (now Nigeria), are held in over 160 museums worldwide. Several German museums began returning Benin Bronzes in 2022, and the Smithsonian's National Museum of African Art returned 29 bronzes in 2023. The British Museum, which holds the largest collection of Benin Bronzes, has been constrained by the British Museum Act of 1963, which prevents the museum from deaccessioning objects unless they are duplicates or damaged. The debate over the Benin Bronzes, the Parthenon Marbles, and other contested collections has forced museums to confront the difference between preserving heritage and possessing it.
The Louvre is the world's most visited art museum, receiving approximately 10 million visitors per year. Its collection spans from ancient civilizations to 1848, with highlights including the Mona Lisa (c. 1503-1519) by Leonardo da Vinci, the Venus de Milo (c. 130-100 BCE), and Liberty Leading the People (1830) by Eugene Delacroix. The Louvre's collection was built through royal patronage, revolutionary nationalization, and Napoleonic conquest, and its history embodies the tensions between preservation and possession that define the modern museum.
The Met holds over 2 million objects spanning 5,000 years of art history. Its collection includes European paintings, Egyptian art (including the Temple of Dendur, installed in a glass-walled room overlooking Central Park), American decorative arts, and one of the world's greatest collections of arms and armor. The Met's 2024 attendance was approximately 5.4 million visitors, making it the most visited art museum in the Americas. The Met's encyclopedic scope, its commitment to collecting across cultures and periods, makes it a model of the universal museum, a concept that has been both celebrated for its ambition and criticized for its imperial origins.
MoMA was the first museum dedicated to modern and contemporary art, and its collection of late 19th and 20th century work is the most influential in the world. The collection includes Picasso's Les Demoiselles d'Avignon (1907), Van Gogh's The Starry Night (1889), Dalí's The Persistence of Memory (1931), and Warhol's Campbell's Soup Cans (1962). MoMA's 2019 expansion and reinstallation, designed by Diller Scofidio + Renfro, reorganized the collection to include more works by women, artists of color, and non-Western artists, addressing criticisms that the museum's narrative of modern art had been too narrow.
Tate Modern, housed in the former Bankside Power Station designed by Sir Giles Gilbert Scott, is the most visited modern art museum in the world, with approximately 5.7 million annual visitors. Its collection of international modern and contemporary art from 1900 onward includes works by Picasso, Matisse, Rothko, Warhol, and Bourgeois. Tate Modern's Turbine Hall, a vast industrial space at the entrance to the museum, has hosted some of the most ambitious commissioned installations of the 21st century, including Olafur Eliasson's The Weather Project (2003) and Ai Weiwei's Sunflower Seeds (2010).
The museum is the institutional endpoint of the art world's infrastructure. Commercial galleries place work with museums as the ultimate validation of an artist's career. Auction houses use museum acquisitions as a benchmark for valuing work. Biennales provide the platform where museum curators discover artists for acquisition. The Kunsthalle is the European counterpart to the museum, offering exhibition space without a permanent collection. Provenance research, the documentation of a work's ownership history, is a core museum function, especially for works acquired during periods of colonial expansion or wartime looting. Repatriation is the process of returning cultural property to its origin communities. For more on how museums fit into the art world, read our post on art history in 10 minutes or explore our guide to Renaissance art and the birth of modern art.
Museums are the one place in the art world where the public can see art without commerce mediating the experience. When you stand in front of a painting at the Met or the Louvre, you are looking at an object that has been preserved, studied, and presented for your benefit, not for sale. The museum's job is to make that encounter possible, and the best museums do it with a level of scholarship, conservation, and curatorial intelligence that no other institution can match.
If you want to understand what museums do, do not just visit the famous galleries. Go to the conservation labs, if they are visible. Read the wall texts, which are written by curators who have spent years studying the works. Look at the provenance information, which tells you where each object came from and how it got to the museum. That history is the museum's real story. For more on the institutions that shape art, read our entries on the commercial gallery and the Kunsthalle, or explore our post on the evolution of art styles.
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