The mansabdars who were assigned the revenue of a tract of land (jagir) were known as jagirdars. The jagirdar used to collect the revenue from the tenants or cultivators residing within the tract of land (or jagir) that he had been assigned by the emperor.
A jagirdar was not supposed to collect any other tax or cess in addition to the land-revenue fixed by the government officials. In other words, jagirdars were under the fullest control of the emperor. This is also evident from the fact that jagirs were by nature transferable.
Further, jagirdari was not a hereditary post. There was no guarantee that a jagirdar's son would also be appointed as jagirdar. Anyway, many changes took place in the Jagirdari system throughout the Mughal rule.