Building blocks are reusable components of business, IT, or architectural capability that can be combined to deliver architectures and solutions. Building blocks can be defined at various levels of detail, depending on the stage of architecture development. In the earlier phases of the ADM cycle (A to D), building blocks are defined in generic terms, such as logical or physical, to provide a high-level view of the architecture. In Phase E: Opportunities and Solutions, building blocks become implementation-specific, meaning that they are linked to specific products, standards, technologies, and vendors that are available in the market. This phase also identifies the delivery vehicles, such as projects, programs, or portfolios, that will realize the building blocks12 References: 1: The TOGAF Standard, Version 9.2, Part II: Architecture Development Method (ADM), Chapter 23: Phase E: Opportunities and Solutions 2: The TOGAF Standard, Version 9.2, Part IV: Architecture Content Framework, Chapter 36: Building Blocks