This assignment requires the development of a web-based gym booking system using HTML, PHP, and MySQL. The system should allow gym members to book fitness classes, considering class schedules, capacity, and user input validation for names and phone numbers. The solution involves creating a database to store class information, available slots, and booking records. The system must handle user input via drop-down menus and text fields, validating data and providing feedback on booking success or failure. It also includes requirements for preventing concurrent booking issues, handling errors, and ensuring code quality through comments and proper formatting. The system should be accessible via a specific URL and meet all the requirements outlined in the assignment brief, including error handling, security, and user-friendly design. The solution emphasizes database interaction, form handling, and adherence to the assignment's constraints and additional requirements, such as preventing code injection and minimizing the use of JavaScript.