How does the concept of services differ from a complete system in software engineering?

The concept of a service in software engineering involves creating a separate, autonomous component that performs a specific function and interacts with other services through well-defined interfaces (e.g., API). A service is usually focused on performing a single task and can be deployed and scaled independently.

A complete system is a collection of all such services and components, combined to solve a broader problem or provide comprehensive functionality. The system includes infrastructure, interactions between services, user interface, and other elements.

Thus, a service is a building block, and a system is a holistic application or platform consisting of many such blocks.