One important source is the official records of the British administration. Every instruction, plan policy decision, agreement, investigation was clearly written up. This produced an administrative culture of memos, notings and reports.
The practice of surveying also became common under the colonial administration. The British believed that a country had to be properly known before it could be effectively administered. In the villages, revenue surveys were conducted.
The effort was to know the topography, the soil quality, the flora, the fauna, the local histories, and the cropping pattern - all the facts as seen necessary to know about to administer the region. From the end of the nineteenth century, Census operations were held every ten years.
These prepared detailed records of the number of people in all the provinces of India, noting information on castes, religions and occupation. There were many other surveys- botanical surveys, zoological surveys, archaeological surveys, anthropological surveys, forest surveys.
Official records tell us what the officials thought, what they were interested in, and what they wished to preserve for posterity. These records do not always help us understand what other people in the country felt, and what lay behind their actions.
For that we have diaries of people, accounts of pilgrims and travellers, autobiographies of important personalities, and popular booklets that were sold in the local bazaars. As printing spread, newspapers were published and issues were debated in public.
Leaders and reformers wrote to spread their ideas, poets and novelists wrote to express their feelings. To understand how history was experienced and lived by the tribels and the peasants, the workers in the mines or the poor on the streets is a more difficult task.