At this level, individuals have a basic understanding of what AJAX is and its purpose. They are familiar with HTTP methods such as GET and POST, and understand the role of XML and JSON data formats in AJAX. However, they may not yet be able to implement AJAX functionality in a practical setting.

Novices can create simple AJAX requests and understand the readyState property. They know how to handle AJAX responses and understand the difference between asynchronous and synchronous requests. They are beginning to apply their knowledge in practical settings, but may still need guidance.

Intermediate users are proficient in using AJAX with jQuery and can handle errors in AJAX requests. They understand AJAX events and know how to send data with an AJAX request. At this level, individuals can independently implement AJAX functionality in various contexts.

Advanced users can use AJAX with different data types and APIs, and understand cross-domain AJAX requests. They also know how to use AJAX with forms. These individuals can solve complex problems using AJAX and can adapt their approach based on specific project requirements.

Experts have a deep understanding of AJAX, including security considerations and performance optimization. They know advanced AJAX techniques and patterns, and can integrate AJAX with other technologies. Experts can design and implement sophisticated AJAX solutions, and provide guidance to others.