Can you explain the principle of level isolation in software architecture?

The principle of layer isolation in software system architecture means dividing the application into independent layers, each responsible for its part of functionality and interacting with others through well-defined interfaces.

This allows:

• Simplifying system maintenance and development — changes in one layer minimally affect others.
• Increasing code reusability.
• Improving testability, as layers can be tested separately.

For example, in a classic three-tier architecture:

• The presentation layer (UI) handles user interaction.
• The business logic layer processes data and implements rules.
• The data access layer works with the database.

Each layer is isolated, and interaction occurs through interfaces or services, which reduces coupling and increases system flexibility.