Why is Uploaded file validation important in Laravel applications, and what problem does it solve for developers?

Why is Uploaded file validation important in Laravel applications, and what problem does it solve for developers? The key reason to understand uploaded file validation is that Laravel applications are usually composed of several layers that must work together predictably. Validation can constrain file size, type, MIME expectations and other file properties. Ignoring that boundary can lead to duplicated logic, poor security, unnecessary database work, or code that is difficult to test. Why it matters in practice: Laravel handles uploaded files through the request object and storage APIs, with validation used to control size, type and other constraints. The specific focus here is uploaded file validation: Validation can constrain file size, type, MIME expectations and other file properties. 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.