The objective of this chapter is to establish a core understanding of software architecture and its significance in the development of complex systems. It defines the scope and characteristics of software architecture, introduces its evolution as a multidisciplinary engineering discipline, and highlights its role in bridging technical and stakeholder concerns. The chapter explores key elements of architectural design, including schematic architecture, architectural views, and non-functional requirements. It also examines the challenges faced in architectural design and clarifies the responsibilities of software architects, thereby promoting a systematic, architecture-driven approach across the software development lifecycle.