Tehsildar
Tehsildar is the term used to describe a tax inspector in India, Pakistan and Bangladesh. They are in charge of obtaining taxes from a Tehsil. The term is assumed to be of Mughal origin, and is perhaps a combination of the words "Tehsil" and "Dar" ("Tehsil", presumably an Islamic word derived from Arabic meaning "revenue collection" and "dar", apparently a Persian word meaning "holder of a position").
The immediate subordinate of a Tehsildar is known as a Naib Tehsildar.
India
British rule
During British rule, a Tehsildar was most likely a stipendiary officer of the government, employed to raise revenue. It was subsequently used by Pakistan and India following their independence from the British Empire. Tehsildar is also known as Talukdar in some states of India.
Independence
Tehsildar are Class II Gazetted Officers in most of the states of India. They implement the various policies of the taluka and are subject to the District Collector. Officers holding the post of Tehsildar preside over matters related to Land, Tax and Revenue. Tehsildar were first appointed as Naib Tehsildars after successful completion of a Civil Services Examination (i.e. PCS in Uttar Pradesh, HPAS in Himachal Pradesh, RAS in Rajasthan, MPPCS in Madhya Pradesh, BAS in Bihar, APPSC in Andhrapradesh or other equivalent exams in other states of India), or promoted from a subordinate post like Kanoongo (also known as Revenue Inspectors). Later on, they get promoted to the post of Tehsildar according to cadre rules.
Each state is divided into districts. The district's senior civil servant is the District Collector/District Magistrate, who is an officer from the IAS cadre. These districts are further subdivided into Revenue Subdivisions or Prants (West India). Each Subdivision is under the charge of an officer designated as a Subdivisional Magistrate (S.D.M.) or Deputy Collector who is a member of the State Civil Services cadre. These subdivisions are divided into various Tehsils or Talukas. These Tehsils or Talukas are administrated by a Tehsildar, also known as a Talukdar in some states of India. The Tehsils/Talukas are further divided by groups of villages. Each group comes under the charge of a Kanoongo (also known as a Revenue Inspector). These villages are put under a village level revenue employee and is known as a Lekhpal or Patwari. This hierarchy is mainly used for administrative activities, including the identification and collection of revenue from land. A separate hierarchy exists for law enforcement in each district.