As per Wikipedia,
A web application framework is a software framework that is designed to support the development of dynamic websites, Web applications and Web services. The framework aims to alleviate the overhead associated with common activities used in Web development.
Today Slashdot posted about a recent wikipedia entry which compares different cheaply available platforms for deciding which is most suitable for your kind of website and as it says, it depends on five measures –
- Maturity of solution
- Size of community of skilled users (to build a team)
- Complexity/ease of use (for neophytes to master)
- Greatest strength of your choice, and the greatest weaknesses of the other two
So using these benchmarks, you can compare these technologies in order to decide which is the best choice for you – PHP5, CakePHP, or RubyOnRails. Here is the detailed Comparison of web application framework.