I am new to propel,any one can explain me about what is the use of it and how to integrate any framework with propel?
Well, since there is an entire website about Propel, full of documentation and the like, I'll bet they can.
You bigger question, I think, is that you probably want to understand what the purpose of an ORM is. In short, it is a way of mapping between a relational database and an OOP framework, but Wikipedia has far more information, so you might want to start there.
You mentioned in a comment that you'd like to combine this with CakePHP. Well here's how: don't unless you already know how to combine them. CakePHP has its own ORM system, so there really is no justifiable use case for having both (legacy code is not excuse -- just choose one!). If you're using Cake, use Cake and rejoice (you can have tea and skip on the or death
)! If you're using Propel, use Propel and go somewhere.