Photographs and Illustrations:

Photographs and illustrations are documents which provide a visual or pictorial representation of a person, place or situation which words fail to describe or find hard to depict. Words cannot tell what Pandit Nehru looked like, only his photograph can do that. Words cannot describe the  Kumbha  mela  in progress at Hardwar or the Burning Ghats of Banaras or the Taj Mahal of Agra as accurately as their respective photographs  can. Similarly, a complicated subject may be easily explained  by a simple illustration. Graphical representation is always helpful in  making readers grasp textual matter easily. A radio or television set cannot be assembled without the help of its drawings. Nor can a building be constructed unless the architect's plan is made available to the engineer. These documents, therefore, form an important part of a library collection.

Microforms:

Microforms are those documents which embody thought in a  reduced form that cannot be read with the  naked eye. They require some device for reading.  They comprise  microfilms,  microfiche, and micro-opaques. These documents are now common in libraries. The reasons for heir popularity are: (1) Micro-forms reduce the bulk of documents  and help the libraries save  considerable space. (2) Out-of-print documents which are either not easily available or too expensive in the original form can be easily acquired in micro-form  (3) Documents in original are too bulky to be transported rapidly. Micro forms, greatly reduced in bulk, are more suitable for easy and quick transportation, as  also for  airlifting. (4) A readable  photocopy can be prepared from a microform easily. 

Microforms are available indifferent varieties and dimensions. Their organisation and maintenance also requires .special care.