Encyclopedia is a useful tool used to get information about any item in any branches. The word ‘Encyclopedia’ is derived from a Greek word ‘enkyklios paideia’ which literally means General Knowledge. The idea of this is derived from modern dictionaries. Dictionaries also provide necessary information like meaning and definitions of any word. But the information provided will be limited.

Encyclopedia provides not only the definitions but also the background, history and step by step evolution of any searched items. ‘Naturalis Historia’ is the first known Encyclopedia. Britannica is a popular encyclopedia available in the modern day’s market. Wikipedia is the most used web based encyclopedia available.