In which way the people get the information about the Indus Valley civilisation?

Explanation

We get valuable information about the Harappan culture/civilisation with the help of different sources. They are as follow:
(i) About 2000 seals are found and of these a great majority carry short inspirations with pictures of the one-horned bull, the buffalo, the tiger and the elephant (art of curving).
(ii) Different type of buildings, roads, street, bath, etc. excavated at Harappa, Mohenjodaro and other sites spark a light on Harappan culture/civilisation.
(iii) The ruins give an idea of city dwelling with good planning and other civic sense clearly.
(iv) Different specimens of art such as sculpture (a red sandstone male torso). The art of pottery (consisted of wheel-made wares, heavy and utilitarian), etc.