Please help me with this
Answers to your 3rd and 4th question are provided below:-
3-The periodisation based on social and economic factors refer to the division of history whether of any particular country or the world as whole on the basis of prevailing economy at that time associated with society.
An example can be cited in order to understand this concept effectively.
During the time of rig Veda when there was not much development in the the society on the basis of technology e releases distinctions and other factors then we divided that particular time on the basis of of employment people opted for their living and how social structure was defined.
1- economy was majorly agrarian and trade was not well developed so if things were exchanged on the lines of barter system to cater to the needs of each other this would come under economic history when we are studying the economy of a country in history.
2- When we study about social division of society in history be mainly consider how society has been structured based on caste class race are cultural practices. We study these factors as per the convenience as this is the only method available due to lack of return documents.
4- Historical change simply refers to the changing of events over the course of time. It is an all-encompassing term - major events, such as wars, and the most miniscule events, such as the winning of a high school football game, are all part of historical change. Historical change happens every day - it takes place with each passing second. Historical change takes place through the process of cause and effect, or in other words, the process by which one thing leads to another, which leads to another, and so on and so forth.
By way of example, let's look at the 1920s. Sometimes called the 'Roaring Twenties,' this decade was much different from the decade that came before it. There was much historical change between, say, 1915 and 1925.
The change of historical process could be traced in all aspects of life that are involved in studying history whether of personal or collective history of any particular country.
It might involve the changes in lives of people like what kind of employment they preferred ,what kind of culture they practiced, it must be noted that the change in culture is not that significant because culture evolves very slowly with time and it does not change rapidly.
The changes in history also include changes in the political process that our country is witnessing.
Change in history is a matter of concern and importance as life cannot be stagnated at one time with the passing time demands grow and for that we will have to change and this particular change that is happening is part of history and with time it becomes history.