Museum collections are widely varied. There are collections of art, of scientific specimens, of historic objects, of living zoological specimens, of cheese and much more. Because there are so many things to collect, most museums have a specific area of specialization. For example, a history museum may only collect objects relevant to a particular county or even a single person, or focus on a type of object such as automobiles or stamps. Art museums may focus on a period, such as modern art, or a region. Very large museums will often have many subcollections, each with its own criteria for collecting. A natural history museum, for example, will have mammals in a separate collection from insects.
Because museums cannot collect everything, each potential new addition must be carefully considered as to its appropriateness for a given museums defined area of interest.