Defining software architecture

In the experience of the author, this question of the software architecture of a system versus its design seems to pop up quite often, in both online as well as offline forums. Hence, let us take a moment to understand this aspect.

Though both terms are often used interchangeably, the rough distinction of architecture versus design can be summarized as follows:

Software architecture is about the design of the entire system, whereas, software design is mostly about the details, typically at the implementation level of the various subsystems and components that make up those subsystems.

In other words, the word design comes up in both contexts, however, with the distinction that the former is at a much higher abstraction and at a larger scope than the latter.

There is a rich body of knowledge available for both software architecture and design, namely, architectural patterns and design patterns respectively. We will discuss both these topics in later chapters of this book.

In both the formal IEEE definition and the rather informal definition given earlier, we find some common, recurring themes. It is important to understand them in order to take our discussion on software architecture further:

Now that you have understood some of the core aspects of software architecture, let us briefly list some of its characteristics.