Operating on MVC conventions, CakePHP assists in organizing files and keeping things structured, which greatly aids complex web application development. It seamlessly connects with databases to create a backend for web apps. With CakePHP's bake feature, the coding process is streamlined - making this technology time-efficient. By enabling easy customization of URLs and offering built-in validation features, CakePHP offers an efficient platform for web development.

• MVC Architecture: CakePHP follows the Model-View-Controller (MVC) architectural pattern. This pattern separates the application into three parts: the Model manages the data and business logic, the View handles the presentation layer, and the Controller mediates between the two.
• Conventions Over Configurations: CakePHP operates under a principle known as conventions over configurations. This means the framework has a default setting for most aspects, allowing developers to start coding immediately, reducing the need to configure settings for every detail.
• Built-In ORM: CakePHP comes with an Object-Relational Mapping (ORM) layer that streamlines interaction with the database. Developers can work with the database using objects rather than SQL, enabling more organized and cleaner code.
• Plugins and Behaviours: CakePHP offers plugin support which makes it modular, allowing developers to re-use code across various projects. Additionally, 'behaviours' can be defined for models, providing a way to organize and package functionality.
• Testing and Debugging: CakePHP supports built-in testing with PHPUnit. It provides error reporting in the local environment, facilitating easy debugging. Additionally, its CRUD scaffolding allows developers to create, read, update, and delete database records, which assists in quick application development.

The popularity and relevance of CakePHP lies in its ability to streamline and simplify the process of web application development. With an in-built database access layer and translation, caching, and validation functionality, CakePHP minimizes the requirement of redundant code lines. The open-source framework is well-equipped to cater to the varying needs of diverse development projects and proves pivotal in enhancing web application performance.

• Enhanced Efficiency: CakePHP offers exceptional programming features that allow developers to write less code and get more functionality. This means projects can be completed in a faster time frame, which benefits both developers and clients.
• Strong Security: Security is a top concern in web development, and CakePHP addresses this with inbuilt security features like CSRF protection, input validation, and SQL injection prevention. These protect against common online threats and ensure data safety.
• MVC Pattern: CakePHP follows the MVC (Model-View-Controller) architecture pattern. This helps developers to clearly separate the business logic from the data and the user interface, which simplifies coding and makes applications easier to manage.
• Rapid Development: With built-in functionalities such as database access, caching, authentication, translation, and validation, CakePHP offers rapid application development, enabling developers to deliver solutions quicker than usual.
• Flexibility: CakePHP is very flexible and provides freedom to developers in terms of customization. Whether it is developing simple web applications or complex systems, developers have the ability to develop and maintain applications easily using CakePHP.