The role of a Data Scientist is very broad as we can't write down all the roles of a data scientist. They perform almost all the operation related to Data.
I think we can't reply exactly is someone ask us what is the role of a doctor. A Doctor perform all the operations or problems related to Health . Simillarly a Data Scientist works on each and every problems related to Data and analyse it so that a normal person without the knowledge of Data Science can use it for the betterment.
A data Scientist generally Collects the Data, analyse, visualize ,Correct and then convert it into simple meaningful information with the skills and knowledge which they learn from Data Science.