If you are talking about the class used in controller ="" and extension ="" on VFP then there is no difference. Both are apex classes. Now there are some patterns which developers use to follow, like main controller which will hold only references, then extension/service class which will have all the logics, database layer/class where all queries will be executed. This is how classes are defined in patterns.
Hi TheRealist 1) Acutully in my knowledge Extension must assign constructor and controller may be r may not be. 2) extension Class override the standard functionalities.
Go through below links it's needful http://www.infallibletechie.com/2012/11/difference-between-standardcontroller.html http://salesforce.stackexchange.com/questions/4041/difference-between-controller-and-extensions
1) Acutully in my knowledge Extension must assign constructor and controller may be r may not be.
2) extension Class override the standard functionalities.
Go through below links it's needful
http://www.infallibletechie.com/2012/11/difference-between-standardcontroller.html
http://salesforce.stackexchange.com/questions/4041/difference-between-controller-and-extensions
let me know the above qurries are helpful r not.
Regards
Raj.