> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upscyatra.in/llms.txt
> Use this file to discover all available pages before exploring further.
# UPSC Glossary: 100+ Key Terms for Civil Services Exam
> Browse 100+ UPSC key terms in Economy, Polity, Geography, Environment, and Science & Tech — each with a precise definition and exam-relevant context.
UPSC tests precise conceptual understanding, not just surface familiarity. You can read the same term in ten newspapers and still get a Prelims question wrong — because UPSC doesn't ask for a headline understanding, it asks for the exact definition, the constitutional basis, the institutional mechanism, or the policy implication. The UPSCYatra Glossary gives you 100+ terms across 7 subject categories, each written with the exam angle explicitly called out, so you're not just learning what a term means — you're learning how UPSC uses it.
## Categories and Key Terms
The economy section covers terms across macroeconomics, public finance, monetary policy, and international trade — the core of GS3 and a major source of Prelims questions.
Key terms include:
* **Fiscal Deficit** — gap between government's total expenditure and revenue receipts plus non-debt capital receipts
* **GDP** — Gross Domestic Product; nominal vs real GDP and the difference between GDP, GNP, and GVA
* **GST** — structure, IGST/CGST/SGST distinction, and the role of the GST Council
* **FRBM Act** — fiscal targets, escape clauses, and the Medium-Term Fiscal Policy Statement
* **FDI vs FPI** — the critical distinction UPSC tests every few years
* **Balance of Payments** — current account, capital account, and why a BoP crisis matters
* **Monetary Policy** — repo rate, reverse repo, SDF, MSF, and how the MPC functions
* **Inflation & Deflation** — CPI vs WPI, headline vs core inflation, and the RBI's inflation targeting mandate
* **CRR** — Cash Reserve Ratio; how it differs from SLR and its monetary policy implications
* **Bank Rate** — and how it differs from the repo rate; a common Prelims trap
* And many more terms covering SEBI, NBFC regulations, priority sector lending, and fiscal federalism
Polity terms are drawn from the Constitution, judicial pronouncements, and parliamentary procedure — the foundation of GS2.
Key terms include:
* **Fundamental Rights** — each Article, reasonable restrictions, and the judicial interpretation history
* **DPSP** — Directive Principles; their non-justiciable nature and the conflict/harmony debate with Fundamental Rights
* **Fundamental Duties** — Article 51A; which ones are legally enforceable and which are not
* **Habeas Corpus, Certiorari, Mandamus, Prohibition, Quo Warranto** — each writ, when it lies, and landmark cases
* **Collegium System** — origin (Three Judges Cases), how it works, and the NJAC controversy
* **Basic Structure Doctrine** — Kesavananda Bharati case, what qualifies as basic structure, and its ongoing relevance
* **Anti-Defection Law** — Tenth Schedule, when it applies, the role of the Speaker, and recent controversies
* And more terms covering emergency provisions, federalism, parliamentary privileges, and constitutional bodies
Geography terms span physical geography, climatology, oceanography, and biogeography — tested in both GS1 and Prelims Environment sections.
Key terms include:
* **Biodiversity Hotspot** — Norman Myers' criteria (1,500+ endemic vascular plants, lost 70%+ original habitat); India's 4 hotspots
* **Biosphere Reserve** — UNESCO's three-zone structure (core, buffer, transition); India's 18 biosphere reserves
* **El Niño** — abnormal warming of central/eastern Pacific; its effects on India's monsoon
* **Indian Ocean Dipole** — positive vs negative IOD and its relationship with Indian rainfall
* **Carbon Sink** — forests, oceans, and soil as carbon stores; the difference between a sink and a reservoir
* **Mangrove** — ecological functions, India's distribution, and why UPSC asks about them in GS3 as well
* **Coral Reef** — bleaching mechanism, India's coral reefs (Lakshadweep, Gulf of Mannar, Andaman), and climate threats
* And more terms on ocean currents, pressure belts, tectonic features, and Indian drainage systems
Environment terms cover ecology, international conventions, and pollution — high-yield for both Prelims and GS3 Mains.
Key terms include:
* **Endemic Species** — species found exclusively in a defined geographic area; distinction from native and exotic species
* **Eutrophication** — nutrient enrichment of water bodies, algal blooms, and hypoxia; anthropogenic causes
* **Kyoto Protocol** — legally binding emission reduction targets, Annex I/II countries, and why it matters despite the Paris Agreement
* **Montreal Protocol** — ozone-depleting substances, the Kigali Amendment (HFCs), and India's compliance obligations
* **Carbon Credit** — cap-and-trade mechanism, CDM, and India's Perform Achieve Trade (PAT) scheme
* And more terms covering CITES, Ramsar Convention, UNFCCC, biological diversity, and pollution standards
Science & Technology terms cover emerging technologies, India's space and defence programmes, and biotechnology — all heavily tested in Prelims.
Key terms include:
* **CRISPR-Cas9** — gene editing mechanism, how it differs from GMOs, and the ethical dimensions UPSC asks about
* **Blockchain** — distributed ledger technology, consensus mechanisms, and government applications in India
* **Chandrayaan** — mission objectives, the significance of the South Pole landing (Chandrayaan-3), and ISRO's upcoming missions
* **Gaganyaan** — India's human spaceflight programme, the role of the Vyommitra robot, and mission status
* **mRNA Vaccine** — mechanism of action, how it differs from conventional vaccines, and COVID-19 context
* And more terms covering 5G, quantum computing, nuclear energy, AI in governance, and India's defence indigenisation
IR terms cover multilateral institutions, regional groupings, and India's foreign policy architecture — essential for GS2 International Relations.
Key terms include:
* **ASEAN** — 10 members, ASEAN-India relations, RCEP, and Act East Policy
* **ADB** — Asian Development Bank; headquarters in Manila, India's borrowing, and its climate finance role
* **BRICS** — current membership after 2024 expansion, New Development Bank, and India's strategic interests
* **G20** — India's 2023 presidency legacy, the G20 vs G7 distinction, and financial stability mandate
* **IMF** — Special Drawing Rights, Article IV consultations, India's quota and voting share
* **NAM** — Non-Aligned Movement; its founding, India's role, and contemporary relevance
* And more terms covering SCO, QUAD, I2U2, SAARC, Commonwealth, and key bilateral treaties
History terms cover the freedom struggle, colonial policies, and social reform movements — the bedrock of GS1 Modern History.
Key terms include:
* **Civil Disobedience Movement** — 1930 launch, Dandi March, the Gandhi-Irwin Pact, and why it was significant despite being suspended
* **Doctrine of Lapse** — Dalhousie's policy, states affected (Satara, Nagpur, Jhansi), and its role in the 1857 revolt
* **Drain of Wealth** — Dadabhai Naoroji's argument, the economic mechanism, and its relevance in GS1 Modern India answers
* **Non-Cooperation Movement** — 1920–22, the Chauri Chaura incident, and what Gandhi's suspension revealed about mass movement strategy
* And more terms covering the Permanent Settlement, Ryotwari and Mahalwari systems, the Press Acts, Indian National Army, and Partition historiography
## What Each Entry Contains
A concise, exam-ready definition that you can reproduce in a Prelims elimination context or use as the opening line of a Mains answer.
An explicit tag — Prelims, Mains GS1/GS2/GS3/GS4, or both — so you know exactly how much depth to go into and where this term is likely to appear.
The specific numbers, dates, institutional names, or case names that UPSC has tested or is likely to test — the facts that make the difference between getting a question right and almost right.
Linked terms that often appear in the same question or require contrast — for example, the Bank Rate entry links to Repo Rate and SDF so you can study the family of concepts together.
## Browsing the Glossary
You can access terms in two ways:
* **Browse by Category** — Select Economy, Polity, Geography, or any other subject to see all terms in that domain, grouped and ordered logically.
* **Search by Term** — Type any term in the search bar to pull up the entry directly. Useful when you encounter a specific word in current affairs or a mock test and need a quick, deep explanation.
Use the Glossary as a live companion during your current affairs reading. When you come across an unfamiliar term in a newspaper article, a government report, or a mock test explanation — don't settle for the surface definition. Open the Glossary entry to get the full UPSC-relevant context: the exam angle, the key facts, and the related terms. A single such lookup often connects a current affairs story to three different parts of the GS syllabus at once.