Data validation is the process of ensuring that the data entered by a user is accurate and meets certain criteria. This can include checking for data types, length, range, and format, as well as applying business rules and constraints.

In web development, data validation is typically performed on the server-side to ensure the security and integrity of the application. It is important to validate user input to prevent security vulnerabilities such as SQL injection or cross-site scripting attacks.

Model binding is the process of mapping incoming data to the properties of a model object. This is commonly used in web frameworks to automatically populate objects with the data submitted by a user through a form.

Model binding can also include data validation, where the framework uses the defined validation rules to check the incoming data before populating the model object. This can help simplify the development process and reduce the risk of errors.

In most web frameworks, data validation and model binding are closely related and often performed together. The framework typically provides tools and APIs to define validation rules and automatically apply them during the model binding process.

Overall, data validation and model binding are important steps in the development process to ensure the accuracy, security, and integrity of the data being processed by an application.