What is the purpose of the controllers in Salesforce?

Standard controllers fetches data and provide to the views such as page, list, dialog or forms. Controlling data for a single record: One of the key functionality of standard controllers is to provide the data, and to facilitate binding a view's controls to the records fields for either display or input.

Hii Sumit,
Standard controllers fetches data and provide to the views such as page, list, dialog or forms. Controlling data for a single record: One of the key functionality of standard controllers is to provide the data, and to facilitate binding a view's controls to the records fields for either display or input.

Hi Sumit,
It depends on your purpose:

• If you want a page with many records, using standard list view, and list actions you could use standard list controller:

<apex:page standardController="Account" recordsetVar="accountsList"...> ... </apex:page>

• If you want to use completely custom functionality and don't really need most of the standard object behaviors, custom controller is a good option, but bear in mind, any standard actions you want to use will have to be implemented in your custom class. A page with a custom controller would use the following attribute:

<apex:page controller="MyApexClass"...> ... </apex:page>