Definitions.
FAR 2.101 is the FAR’s master definitions section, and it is foundational because it tells readers how key words and terms must be understood throughout the regulation. It covers the general rule that a defined term has the same meaning across the FAR unless context or another FAR part, subpart, or section requires a different meaning, and it explains how cross-referenced definitions control when a term is redefined elsewhere. The section then begins the FAR’s long list of defined terms, including acquisition, acquisition planning, Activity Address Code (AAC), adequate evidence, advisory and assistance services, the three subcategories of advisory and assistance services (management and professional support services, studies/analyses/evaluations, and engineering and technical services), affiliates, agency head, alternate, and architect-engineer services. In practice, this section matters because these definitions drive how contracting officers draft solicitations, evaluate requirements, classify services, apply socioeconomic and organizational rules, and interpret clauses and procedures consistently. Contractors also rely on these definitions to understand what the Government is buying, what standards apply, and how FAR requirements may affect competition, performance, and compliance. Because FAR 2.101 is a gateway section, a misread definition can affect the entire acquisition strategy, contract administration approach, and legal analysis of a procurement.