Hard science — inquiry into the nature of the “hard materials” like rocks.
Social science — inquiry into shared meanings on the material stuff around us, including the “hard materials” like mountains, and “soft intangible stuff” like taboos and beliefs, prices, and demand.
A lot of people assume “hard” means the serious stuff and social science as the easy and abstract stuff. Nothing could be further from the truth.
Economics is a social science. Sadly, the fascination with it being “hard” is largely to be seen as the cool tough stuff. Inferiority complex, if you may.