Jan A.P. Hoogervorst: Three core imperatives are essential for modern businesses and organizations: seamless integration of customer and operational processes, agility, and the ability to change. These imperatives are relevant in view of successfully executing strategic choices, but all too often not satisfied. Businesses and organizations are complex adaptive socio-technical systems and can be viewed from two fundamentally different perspectives: the functional (black-box) perspective and the constructional (white-box) perspective. Management and governance of businesses and organizations regard the functional, black-box perspective, which is inherently ill-suited for addressing the imperatives mentioned. It will be argued that establishing system integration, agility and change requires a focus on the system’s design, hence necessitates the constructional perspective. The concept of architecture is considered fundamental for operationalizing the constructional perspective. Next to the more familiar notion of technology architecture, the concepts of business, organizational and information architecture are formally introduced and elucidated. Various domains within these architectures will be highlighted, whereby the importance of coherence and consistency is stressed, especially in view of the ability to change. Collectively, the four architectures are labeled Enterprise Architecture. Finally, enterprise architecture will be positioned as a crucial means for linking strategy development and execution.