Conservation is the profession devoted to the preservation of cultural property for the future. Conservation activities include examination, documentation, treatment, and preventive care, supported by research and education. (Definition taken from the Core Documents of The American Institute for Conservation of Historic & Artistic Works - see external links.) Preventive conservation is an important element of museum policy and collections care. It is an essential responsibility of members of the museum profession to create and maintain a protective environment for the collections in their care, whether in store, on display, or in transit. A museum should carefully monitor the condition of collections to determine when an object or specimen may require conservation-restoration work and the services of a qualified conservator-restorer. The principal goal should be the stabilisation of the object or specimen. All conservation procedures should be documented and as reversible as possible, and all alterations should be clearly distinguishable from the original object or specimen. (Defenitions taken from The ICOM Code of Professional Ethics - see external links.) Art conservation is not identical to art restoration. Restoration is a process that attempts to return the work of art to some previous state that restorer imagines to be "original". This was commonly done in the past. However, in the late 20th century a separate concept of conservation was developed that is more concerned with preserving the work of art for the future, and less with making it look pristine. Restoration is controversial, since it often involves some irreversible change to the original material of the artwork with the goal of making it "look good." The attitude of restorers in recent years is to make all the restoration they undertake reversible. The use of watercolor paints to inpaint damages on fresco is an example of a technique utilized to achieve almost complete reversibility.
Art conservation can involve the cleaning and stabilization of art work. Ideally, any process used is reversible, departures from that ideal not being undertaken lightly. Cleaning is not a reversible process and can sometimes be controversial due to fears that cleaning would damage a piece, or on the grounds that damage or residue forms part of the history of a given piece and should not be modified. Michaelangelo's statue of David has undergone two cleanings to remove dirt that had accumulated on the statue's surface.
In North America, five colleges/universities offer a graduate degree in art conservation:
In addition, the University of Texas, Austin offers a Certificate of Advanced Study in the conservation of library and archival materials as part of its Master of Science in Information Studies program.

The University of Delaware (in association with Winterthur Museum)
Buffalo State College, New York
Queen's University, Ontario
New York University
University of California, Los Angeles/Getty Program in Archaeological and Ethnographic Conservation Canadian Conservation Associations

ArtWatch International
Cultural heritage
Australian Institute for the Conservation of Cultural Material AICCM
Canadian Conservation Institute http://www.cci-icc.gc.ca/