Census glossary
54 census terms defined precisely, using official Census of India definitions where they exist. Terms marked UPSC appear regularly in civil-services exams.
Methodology
Houselisting (Houselisting and Housing Census, HLO) UPSC
Houselisting is the first phase of the Indian census, in which every building and census house is identified, numbered and listed, and data are collected on housing conditions, household amenities (drinking water, latrine, lighting, cooking fuel, internet) and assets.
Population Enumeration UPSC
Population Enumeration (PE) is the second phase of the census, in which an enumerator canvasses the Household Schedule for every individual, covering name, age, sex, marital status, religion, SC/ST status and (in 2027) caste, education, language, disability, migration, economic activity and fertility.
Reference Date UPSC
The reference date is the single point in time to which the entire census count relates: everyone alive at that moment is to be counted, wherever enumeration physically happens over the preceding weeks.
Census Moment UPSC
The census moment is the precise instant — 00:00 hrs of the reference date — that separates who is counted from who is not.
De Facto Method UPSC
Under the de facto method, people are counted at the place where they are physically present at the census moment, rather than at their usual home. A pure de facto count must be completed very quickly (ideally in one night) to avoid double counting of travellers.
De Jure Method UPSC
Under the de jure method, each person is counted at their place of usual residence, regardless of where they happen to be at the census moment. Its practical advantage is that enumeration can be spread over many days without risk of double counting travellers.
Canvasser Method UPSC
In the canvasser method the enumerator visits each household, asks the questions and records the answers personally — as opposed to the 'householder method', where the household fills the form itself.
Synchronous Census UPSC
A synchronous census is one conducted simultaneously across the entire country with reference to a single moment, so results are comparable everywhere.
Self-Enumeration UPSC
Self-enumeration is 'a process where respondents fill out, complete, and submit the census schedule themselves, rather than having it done by a census enumerator' (official Census 2027 FAQ).
Revisional Round UPSC
The revisional round is the short mop-up visit after the main enumeration period that updates the count to the census moment.
Pre-Test UPSC
A pre-test is a full field rehearsal of census questionnaires, procedures, apps and training conducted on a sample of areas before the real operation.
Houselisting Schedule UPSC
The Houselisting Schedule (formally the Houselist and Housing Schedule) is the questionnaire canvassed in Phase 1.
Household Schedule UPSC
The Household Schedule is the Phase 2 (Population Enumeration) questionnaire, canvassed person by person for every member of every household. On August 14, 2026 the MHA notified the full set of 40 questions for Census 2027 through the Office of the Registrar General, India.
Census House UPSC
A census house is a building or part of a building used or recognised as a separate unit because it has a separate main entrance from the road, common courtyard or staircase.
Drop-in Centre UPSC
In census-operations literature, a drop-in centre is a staffed help point where residents can get assistance completing or submitting census forms — a concept some countries pair with self-enumeration.
Census 2027 Digital Census UPSC
Census 2027 is India's first digital census: data are captured on mobile apps and a web portal instead of the roughly 30 crore paper schedules of past censuses, with direct field-to-server transmission.
Self-Enumeration ID (SE ID) UPSC
The Self-Enumeration ID is the unique 11-digit identifier, prefixed with 'H', generated when a household successfully submits its details on the Census 2027 Self-Enumeration Portal.
Demographic
Household UPSC
In the Census of India, a household is 'a group of persons who normally live together and take their meals from a common kitchen, unless the exigencies of work prevent any of them from doing so.' Members may be related, unrelated, or a mix — the test is co-residence and a common kitchen, not blood or marriage.
Normal Household UPSC
A normal household is the residual — and by far the largest — category of census household: any household that is neither an institutional household nor a houseless household.
Institutional Household UPSC
An institutional household is a group of unrelated persons who live in an institution and take their meals from a common kitchen. Census examples include boarding houses, messes, hostels, hotels, rescue homes, jails, ashrams and orphanages.
Houseless Population UPSC
Houseless households are those that do not live in buildings or census houses but in the open — on roadsides and pavements, in hume pipes, under flyovers and staircases, in places of worship, mandaps or on railway platforms.
Sex Ratio UPSC
In Indian census usage, the sex ratio is the number of females per 1,000 males in the population (note: this is the inverse of the males-per-100-females convention used in many countries).
Child Sex Ratio UPSC
The child sex ratio (CSR) is the number of females per 1,000 males in the 0–6 age group, calculated from census age returns. Because it reflects births over roughly the previous seven years, it is the census's most sensitive indicator of sex-selective practices and differential survival of girls.
Literacy Rate (Census Definition) UPSC
The census treats as literate any person aged seven and above who can both read and write with understanding in any language. No formal schooling or certificate is required; ability to read but not write is insufficient.
Work Participation Rate UPSC
The work participation rate (WPR) is the percentage of total workers (main plus marginal) to total population.
Main Worker UPSC
A main worker is a person who worked for the major part of the reference period — that is, six months (183 days) or more in the year preceding enumeration — in any economically productive activity.
Marginal Worker UPSC
A marginal worker is a person who worked at some time during the year preceding enumeration but for less than six months (183 days) — typically seasonal agricultural labourers, casual workers and others with intermittent work.
Dependency Ratio UPSC
The dependency ratio compares the population in 'dependent' ages to the working-age population. Internationally it is usually (0–14 plus 65+) per 100 persons aged 15–64; Indian analysis often uses a 15–59 working-age band, counting children under 15 and persons 60+ as dependents.
Urban Agglomeration UPSC
An urban agglomeration (UA) is 'a continuous urban spread constituting a town and its adjoining outgrowths, or two or more physically contiguous towns together with or without outgrowths of such towns.' Since 2001 a UA must contain at least one statutory town, and its total population (all constituents combined) must be at least 20,000.
Census Town UPSC
A census town is a settlement that the census treats as urban on demographic-economic criteria even though it has no urban local body and is legally a village.
Statutory Town UPSC
A statutory town is any place with a municipality, municipal corporation, cantonment board, notified town area committee or similar urban local body constituted under law by the State/UT government — irrespective of its population size, density or economic profile.
Million-Plus City UPSC
A million-plus city is an urban agglomeration or standalone town with a population of one million (10 lakh) or more. In Census 2011, 53 of the 468 Class I UAs/towns crossed this threshold, and three — Greater Mumbai, Delhi and Kolkata — exceeded ten million, a class often called mega cities.
SC/ST Enumeration UPSC
Every Indian census since 1951 has recorded whether a person belongs to a Scheduled Caste or Scheduled Tribe, as notified for each State/UT under the Constitution (Scheduled Castes) Order, 1950 and the Constitution (Scheduled Tribes) Order, 1950.
Caste Enumeration UPSC
Caste enumeration means recording every respondent's caste, not just SC/ST status. The last census to publish full caste data was 1931; since 1951 only SCs and STs were enumerated.
Mother Tongue UPSC
The census defines mother tongue as 'the language spoken in childhood by the person's mother to the person.' If the mother died in infancy, it is the language mainly spoken in the person's home in childhood; for infants and deaf-mutes, the language usually spoken by the mother is recorded; in case of doubt, the language mainly spoken in the household.
Migration (Place of Birth / Last Residence) UPSC
The census measures migration two ways. By place of birth: a person enumerated in a place different from their birthplace is a 'lifetime migrant'.
Fertility Questions UPSC
Census fertility questions are asked of ever-married women (currently married, widowed, divorced or separated) and traditionally cover: number of children ever born (by sex), number of children surviving, and children born alive during the last one year.
Cultivator and Agricultural Labourer UPSC
Within the census's four-fold classification of workers, a cultivator is a person engaged in cultivation of land owned or held from government or private persons for payment in money, kind or share — direction and supervision of cultivation count, but working on another person's land purely for wages does not.
Administrative
Enumerator UPSC
The enumerator is the field functionary who actually conducts the census — visiting every household in an assigned block, canvassing the schedule and, in 2027, recording answers in the mobile app and verifying self-enumeration IDs.
Supervisor UPSC
A supervisor is the first-line quality-control officer of the census, overseeing a group of enumerators and their blocks within a charge.
Charge UPSC
A charge is the intermediate census jurisdiction between the district and the block — typically a tehsil/taluk/community development block in rural areas or a town/municipal ward area in urban areas — headed by a Charge Officer.
Houselisting Block (HLB) UPSC
The houselisting block is the smallest operational unit of Phase 1 — the patch of territory assigned to one enumerator for houselisting, demarcated so the whole country is covered without omission or duplication and workloads stay even.
Enumeration Block (EB) UPSC
The enumeration block is the basic building block of Population Enumeration: the compact area assigned to a single enumerator for the person-by-person count, designed for complete coverage without omission or duplication and equitable workload.
Administrative Unit Hierarchy UPSC
Census data are collected and published through a fixed territorial hierarchy: India → State/UT → District → Sub-district (tehsil/taluk/CD block) → Village (rural) or Town/Ward (urban) → houselisting/enumeration block.
Census Management and Monitoring System (CMMS) UPSC
The Census Management and Monitoring System (CMMS) is the centralised web portal built for Census 2027 to plan, manage, execute and monitor the entire census on a near real-time basis.
HLO Mobile Application UPSC
The Houselisting and Housing Census (HLO) Mobile Application is the secure data-collection app enumerators use in Phase 1 of Census 2027 — the instrument that makes this India's first digital census.
Houselisting Block Creator (HLBC) UPSC
The Houselisting Block Creator (HLBC) is a web-based mapping application developed for Census 2027 that lets Charge Officers digitally create houselisting blocks using satellite imagery.
National Population Register (NPR) UPSC
The National Population Register is a register of the 'usual residents' of India — citizens and foreigners alike — prepared under the Citizenship Act, 1955 and the Citizenship (Registration of Citizens and issue of National Identity Cards) Rules, 2003, and maintained by the Registrar General of India.
Registrar General and Census Commissioner of India (RGI/ORGI) UPSC
The Office of the Registrar General and Census Commissioner, India (ORGI), under the Ministry of Home Affairs, is the authority that conducts the Census of India.
Houselisting Operations Timeline (State Windows) UPSC
Unlike Population Enumeration, which is synchronised nationally to one reference moment, Census 2027's houselisting phase is staggered: within the April 1 – September 30, 2026 national window, each State/UT government chose its own 30-day field period, preceded by its own 15-day self-enumeration window.
Legal
Census Act, 1948 UPSC
The Census Act, 1948 is the statute under which every Indian census is conducted (census is a Union subject, entry 69 of the Union List).
Confidentiality Provision (Section 15) UPSC
Section 15 of the Census Act, 1948 makes all individual census records strictly confidential: no person has a right to inspect any book, register, record or schedule made by a census officer, and no entry in them is admissible as evidence in any civil proceeding, or in criminal proceedings other than prosecution under the Act itself.
Gazette Notification UPSC
A gazette notification is the formal instrument by which census decisions acquire legal force, published in the Gazette of India under the Census Act, 1948.
Delimitation UPSC
Delimitation is the readjustment of Lok Sabha and Assembly seat allocations and constituency boundaries after each census, mandated by Articles 81, 82 and 170 of the Constitution and carried out by a Delimitation Commission.