What is Unit tests in Laravel, and what role does it play in a real application?

What is Unit tests in Laravel, and what role does it play in a real application? In Laravel, unit tests should be understood as part of a larger application architecture rather than as an isolated API call. Unit tests focus on isolated classes or functions with limited framework and database interaction. A strong understanding includes its purpose, the layer where it belongs, the data or request flow it affects, and the situations where another mechanism may be more appropriate. Practical context: Laravel provides testing support for unit and feature tests so teams can verify business rules and application behavior automatically. The specific focus here is unit tests: Unit tests focus on isolated classes or functions with limited framework and database interaction. This question is designed to test not only terminology, but also how the concept fits into Laravel's request, application, database, security, or deployment workflow.