What does the Mandatory field validation ensure?

Mandatory field validation is a critical aspect of form design and user input handling in applications. It ensures that essential fields must be filled by users before they can proceed. This validation is crucial because it helps maintain data integrity and ensures that the application receives all the necessary information needed for processing. By requiring certain fields to be completed, developers can prevent incomplete submissions that could lead to errors or issues later in the workflow.

For instance, in a registration form, fields such as email address and password are typically marked as mandatory, ensuring that users cannot submit the form without providing these key pieces of information. Consequently, this validation enhances the user experience by guiding users to provide the required data upfront, which can streamline processes and improve overall functionality.