Software architecture is defined as the strategic design of an activity concerned with global requirements. Its solution is implemented in programming paradigms, architectural styles, component-based software engineering standards, architectural patterns, security, scale, integration, and law-governed regularities. Functional design, also described as tactical design, is an activity concerned with local requirements governing a solution such as algorithms, design patterns, programming idioms, refactoring, and low-level implementation. In this paper, I would like to introduce some concepts of software architecture and software design, as well as the relationship between them