Software Architecture
Software architecture is the collection of fundamental decisions about a software product/solution designed to meet the project's quality attributes, or architectural requirements. The architecture includes the main components, their main attributes, and their collaboration (interactions and behavior) to meet the quality attributes. Architecture can and usually should be expressed in several levels of abstraction, where the number of levels depends on the project's size.
Architecture occurs early. It should represent the set of earliest design decisions that are both hardest to change and most critical to get right.
Architecture is an attribute of every system. Whether or not its design was international, every system has an architecture.
Architecture breaks a system into components and sets boundaries. It doesn't need to describe all the components, but it usually deals with the major components of the solution, and their interfaces.
Architecture is about relationships and component interaction. We are interested in the behaviors of the component as it can be discerned from other components interacting with it. Also, it doesn't have to describe the complete characteristics of components, but it mainly deals with their interfaces and other interactions.
Architecture explains the rationale behind the choices. It is important to understand the reasoning as well as the implications of the decisions made in the architecture since their impact on the project is large. Also, it may be beneficial to understand what alternatives were weighted and abandoned. This may be important for future reference, if and when things needs to be reconsidered and for anyone new to the project that needs to understand the situation.
There isn't a single structure that is the architecture. There's a need to look at the architecture from different directions or viewpoints to fully understand it. One or even a handful diagrams is not enough to be called architecture.
In order for a software system’s architecture to be intentional, rather than accidental, it should be communicated. Architecture is communicated from multiple viewpoints to cater the needs of the different stakeholders. An architectural style is a description of component types and their topology, together with a set of constraints on how they can be used.
