Microfilm is a film on which small photographs of documents are recorded, usually at a reduction in size. The microfilm can then be used to produce copies of the original documents, which can be viewed using a microfilm reader. Microfilming is often used to preserve historical documents or to create a permanent record of important documents, as film is more durable than paper. Microfilm is also used to store large numbers of documents in a smaller space, as the reduced size allows more documents to be stored in a given area.