A set is a place with an artificial nature that creates the illusion of a real or imagined place. In filmmaking

Filmmaking

Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...

 there are many reasons to build or use a set instead of traveling to a real location. Factors such as Budget

Budget

A budget is a financial plan and a list of all planned expenses and revenues. It is a plan for saving, borrowing and spending. A budget is an important concept in microeconomics, which uses a budget line to illustrate the trade-offs between two or more goods...

, time, the need to control the environment, or the fact that the place does not exist can be reasons to film on a set. Sets are normally constructed on a film studio backlot

Backlot

A backlot is an area behind or adjoining a movie studio, containing permanent exterior buildings for outdoor scenes in filmmaking or television productions, or space for temporary set construction....

 or sound stage

Sound stage

In common usage, a sound stage is a soundproof, hangar-like structure, building, or room, used for the production of theatrical filmmaking and television production, usually located on a secure movie studio property.-Overview:...

, but any place that has been modified to give the feel of another place is a set.