What is sharing class in Salesforce?

Hi,

With sharing Keyword: This keyword enforces sharing rules that apply to the current user. If absent, code is run under default system context. Use the with sharing keywords when declaring a class to enforce the sharing rules that apply to the current user. Use With Sharing when the User has access to the records being updated via Role, Sharing Rules, Sales Teams – any sort of sharing really.

Example:

public with sharing class sharingClass {

// Code here

}

Without sharing keyword: Ensures that the sharing rules of the current user are not enforced. Use the without sharing keywords when declaring a class to ensure that the sharing rules for the current user are not enforced. For example, you may want to explicitly turn off sharing rule enforcement when a class acquires sharing rules when it is called from another class that is declared using with sharing. Without Sharing is reserved for cases where the User does not have access to the records, but there is a need to update them based on user input.

public without sharing class noSharing {

// Code here

}

Some things to note about sharing keywords:

The sharing setting of the class where the method is defined is applied, not of the class where the method is called. For example, if a method is defined in a class declared with with sharing is called by a class declared with without sharing, the method will execute with sharing rules enforced.
If a class isn’t declared as either with or without sharing, the current sharing rules remain in effect. This means that the class doesn’t enforce sharing rules except if it acquires sharing rules from another class. For example, if the class is called by another class that has sharing enforced, then sharing is enforced for the called class.
Both inner classes and outer classes can be declared as with sharing. The sharing setting applies to all code contained in the class, including initialization code, constructors, and methods.
Inner classes do not inherit the sharing setting from their container class.
Classes inherit this setting from a parent class when one class extends or implements another.

Thanks