An exhibition, in the most general sense, is an organised presentation and display of a selection of items. In practice, exhibitions usually occur within a cultural or educational setting such as a museum, art gallery, park, library, exhibition hall, or World’s fairs. Exhibitions can include many things such as art in both major museums and smaller galleries, interpretive exhibitions, natural history museums and history museums, and also varieties such as more commercially focused exhibitions and trade fairs. In British English the word “exhibition” is used for a collection of items placed on display, and the event as a whole, which in American English is usually an “exhibit”. In both varieties of English each object being shown within an exhibition is an “exhibit”. In common usage, “exhibitions” are considered temporary and usually scheduled to open and close on specific dates. While many exhibitions are shown in just one venue, some exhibitions are shown in multiple locations and are called travelling exhibitions, and some are online exhibitions. Exhibitions featuring especially fragile or valuable objects, or live animals—may be shown only during a formal presentation, under the close supervision of attendant or educator. Temporary exhibits that are transported from institution to institution are traveling exhibits. Though exhibitions are common events, the concept of an exhibition is quite wide and encompasses many variables. Exhibitions range from an extraordinarily large event such as a World’s fair exposition to small one-artist solo shows or a display of just one item. Curators are sometimes involved as the people who select the items in an exhibition. Writers and editors are sometimes needed to write text, labels and accompanying printed material such as catalogs and books. Architects, exhibition designers, graphic designers and other designers may be needed to shape the exhibition space and give form to the editorial content. Organizing and holding exhibitions also requires effective event planning, management, and logistics.