OG0-091 Domain 2: Core Concepts (7.5%) - Complete Study Guide 2026

What Domain 2 Actually Tests

Domain 2: Core Concepts is one of three foundational domains - alongside Domain 1: Basic Concepts and Domain 3: Introduction to the ADM - that each carry 7.5% of the OG0-091 exam. On a 40-question exam, that translates to roughly three questions, which sounds small until you realize this domain supplies the vocabulary that every other domain depends on. You cannot reason correctly about ADM Phases or Architecture Governance if you misunderstand what TOGAF means by "Enterprise Architecture," "Architecture Framework," or the four architecture domains.

Core Concepts is the part of the TOGAF 9 Standard that defines the building-block terminology of the entire framework: what an enterprise is in TOGAF's context, what an architecture framework does, how the Architecture Development Method (ADM) relates to the Enterprise Continuum, and how the four architecture domains fit together. If you have not read our broader OG0-091 Exam Domains 2026: Complete Guide to All 11 Content Areas, start there to see how Domain 2 fits alongside the other ten content areas before drilling into this one.

Why Core Concepts Sits Under Every Other Domain

The Open Group's exam blueprint front-loads Basic Concepts, Core Concepts, and Introduction to the ADM for a reason: together they cover 22.5% of the exam and form the conceptual floor for the remaining 77.5%, which includes the heavily weighted ADM Phases domain at 22.5% and ADM Guidelines and Techniques at 15%. If you skip Core Concepts and jump straight into memorizing ADM phase inputs and outputs, you will find yourself constantly backfilling definitions mid-study, which slows retention.

Our OG0-091 Study Guide 2026: How to Pass on Your First Attempt recommends sequencing the three foundational domains first precisely because Core Concepts terminology - architecture domains, stakeholders, concerns, building blocks (covered more deeply in Domain 9) - recurs constantly once you reach ADM-specific material.

Key Definitions You Must Memorize

Because OG0-091 is a closed-book, simple multiple-choice exam based directly on the TOGAF 9 Standard, Version 9.2, precision in terminology matters. Domain 2 questions are frequently definition-matching or "which statement best describes" style items. Candidates should be able to state, in TOGAF's own language, the difference between:

• Enterprise - any collection of organizations with common goals, which may be larger than a single company or department.
• Architecture - used in two senses in TOGAF: a formal description of a system, and the structure of components, their relationships, and design principles.
• Enterprise Architecture - the holistic view combining business, data, application, and technology perspectives across the enterprise.
• Architecture Framework - a foundational structure or set of structures used to develop a broad range of different architectures.
• Stakeholder - an individual, team, or organization with interests in, or concerns about, the outcome of the architecture.

These definitions sound simple, but exam distractors often swap details between similar-sounding terms - for example, confusing "architecture framework" with "architecture repository," or conflating "enterprise" with "organization." Precision, not general understanding, is what separates a correct answer from a plausible-sounding wrong one.

The Four Architecture Domains (BDAT)

One of the most testable ideas in Domain 2 is the concept of the four architecture domains, often abbreviated BDAT:

• Business Architecture - business strategy, governance, organization, and key business processes.
• Data Architecture - the structure of an organization's logical and physical data assets and data management resources.
• Application Architecture - a blueprint for individual application systems, their interactions, and their relationships to core business processes.
• Technology Architecture - the logical software and hardware capabilities needed to support the deployment of business, data, and application services.

Expect Domain 2 questions to ask you to match a description to the correct domain, or to identify which domain a given artifact belongs to. This foundation directly supports later material: Domain 5's ADM Phases B, C, and D map one-to-one onto Business, Data/Application, and Technology architecture respectively, so nailing the BDAT model here pays off again when you study OG0-091 Domain 3: Introduction to the ADM (7.5%) - Complete Study Guide 2026.

TOGAF Document Structure and Parts

Core Concepts also expects familiarity with how the TOGAF 9.2 standard itself is organized. The document is divided into parts, each corresponding to a major exam domain area: an introduction and definitions section, the Architecture Development Method (ADM), ADM Guidelines and Techniques, the Architecture Content Framework, the Enterprise Continuum and Tools, the TOGAF Reference Models, and the Architecture Capability Framework (which underpins Architecture Governance). Recognizing this structure helps you understand why the OG0-091 exam blueprint itself has 11 domains - each domain roughly mirrors a part or major chapter of the standard.

This is a useful mental model: if a question feels like it belongs to "structure and terminology," it's Domain 2; if it's about method steps, it's Domain 3 or Domain 5; if it's about maturity and reuse of architecture assets, it's Domain 4, covered in OG0-091 Domain 4: The Enterprise Continuum and Tools (10%) - Complete Study Guide 2026.

Question Style and Format on the Exam

OG0-091 consists of 40 simple multiple-choice questions delivered in 60 minutes at a Pearson VUE test center or via OnVUE remote proctoring. There is no scenario-based scoring model like the Part 2 exam - every question has one correct answer chosen from a short list of options. For Domain 2 specifically, expect the question stem to present a term or short statement and ask you to identify the matching TOGAF definition, or to present four definitions and ask which one correctly describes a named concept.

Because the exam is closed book and supervised, you cannot look up wording during the test. This makes rote familiarity with TOGAF's precise phrasing more valuable here than in domains that test applied judgment. If you're unsure how demanding this actually feels in practice, our breakdown in How Hard Is the OG0-091 Exam? Complete Difficulty Guide 2026 walks through why terminology-heavy domains like this one trip up candidates who only skim the standard.

Where to Slot Domain 2 in Your Study Plan

Because Domain 2 is short but foundational, treat it as an early, focused pass rather than something you revisit repeatedly. A practical way to fit it into a broader plan:

This sequencing mirrors the approach in our full OG0-091 Study Guide 2026: How to Pass on Your First Attempt, which allocates early weeks to definitional domains before moving into the heavier ADM Phases and Guidelines material.

Common Traps in Core Concepts Questions

Candidates who have studied ADM Phases extensively sometimes underperform on Domain 2 because they assume terminology questions are "easy" and skip careful review. Common mistakes include:

• Confusing "Architecture Framework" (a structure for developing architectures) with "Architecture Repository" (a store of architecture outputs), a Domain 4 concept.
• Mixing up the four architecture domains when a question describes a hybrid artifact, such as a data flow diagram that touches both Data and Application architecture.
• Assuming "Enterprise" means "company" - TOGAF's definition is broader and can include partial organizations or extended supply chains.
• Overlooking how Core Concepts terms connect to Stakeholder Management and Views/Viewpoints, tested more heavily in OG0-091 Domain 1: Basic Concepts (7.5%) - Complete Study Guide 2026.

Run timed practice sets that mix Domain 1 and Domain 2 questions together, since the two domains share a similar testing style and are easy to blur if you study them separately.

Registration, Fees, and What Passing Gets You

OG0-091 is governed by The Open Group and delivered through Pearson VUE, either at a physical test center or via OnVUE remote proctoring. For 2026, candidates pay a $375 exam booking fee or a $400 retail voucher fee. There are no prerequisites - anyone can register and sit the exam directly. The full breakdown of fees, vouchers, and what's included is covered in OG0-091 Certification Cost 2026: Complete Pricing Breakdown.

Passing OG0-091 with a score of 60% (24 out of 40) earns the TOGAF 9 Foundation certification and counts as partial credit toward the combined TOGAF 9 Certified designation if you later pass OG0-092 (Part 2). TOGAF 9 Foundation does not expire and carries no renewal requirement, which makes the upfront study investment - including mastering domains like Core Concepts - a one-time effort. For a wider look at career impact, see OG0-091 Jobs and Is the OG0-091 Certification Worth It? Complete ROI Analysis 2026.

You can build familiarity with the exact question format described above by running timed practice sessions on our OG0-091 practice test platform, which lets you isolate Domain 2 questions and see exactly how terminology is tested before exam day.

FAQ