Zend Framework came in the technical market in early 2005. At that time other framework such as Ruby on Rails and Spring Framework were gaining popularity in the web development community. In very short period Zend has captured the market and now Zend framework is behind thousands of web application running worldwide.
Zend Framework is an open-source software framework for PHP5. Its biggest strength is its highly modular Model-View-Controller design, which makes the code more reusable and easier to maintain. Zend's flexible architecture is its second strength that helps to build interactive web applications with an ease.
MVC (Model View Controller) architecture separate the data and user interface that means developers it enables developers to make changes in database without affecting the user interface and similarly developers can make changes in user interface without affecting the data. The controller separates data access and business logic from data representation and user interaction.
Zend's MVC architecture is the best one for Web application development. It enables the separation of business logic from user interface design. If we take a look on CakePHP then CakePHP has very strict naming and code organization conventions while Zend only enforces conventions when employing its MVC capabilities.
Zend supports all the databases including Oracle, MySQL, SQLite, PostgreSQL etc. PHP developers can utilize the Zend's various components without developing it within the framework structure. Zend framework is the first choice of developer when they want more control over application design and built-in support for web services as it provides the high degree of flexibility in application development.