How many custom controllers can we have per Visualforce page in Salesforce?

Hi Deepak,

We have three types of controllers that we use on Visualforce Page,

1. Standard Controller : Standard controllers will have same logic and functionality used standard visualforce pages. No Apex code is required in Standard Controllers

Syntax: <apex:page standardController="Account">

2. Custom Controller : When a developer needs different logic and functionality he/she may write their own Apex      controller class. Custom controller’s will not provide default functions like standard controllers.

Syntax : <apex:page controller="ClassName">

3. Extensions : If we want to use both custom controller functionality and standard controller functionality we use               extension controllers. Extension Controllers begins with Standard controller and extended or overridden with custom   controller with custom apex code.

Syntax: <apex:page standardController="Äccount" extensions="ClassName, ClassName2">