Historians divide the past into periods on the basis of economic and social factors to characterise the
major elements of different moments of the past.
(i) The historians faced a lot of problems because time itself reflects changes in social and economic,
organisation, in the persistence and transformation of ideas and beliefs.
(ii) Therefore, describing the entire period as one historical unit is not without its problems.
(iii) "Modernity”" also carries a sense of material progress and intellectual advancement.
(iv) The study of time is made somewhat easier by dividing the past into large segments periods which
possess shared characteristics.