Why Keyword “without Sharing” Is Introduced In Salesforce Apex?

Hi,

Let’s take example, there is classA declared using “with sharing” and it calls classB method. classB is not declared with any keyword then by default “with sharing” will be applied to that class because originating call is done through classA. To avoid this we have to explicitly define classB with keyword “without sharing”.

Thanks

When we invoke some controller within another controller, If called or calling controller (only one) is attached with "with sharing " keyword then sharing rule will be enforced in both the class. to avoid that you need to use "without sharing" keyword in the controller in which sharing rules should not be enforced.