To Simplify the explanation further : there are two modes in which apex executes - User Mode and System Mode .
Where the code that Executes in User mode will keep the Sharing Model in mind and access only those records and objects which are available to the user.
Where as the System mode executes irrespective of Sharing model.
Based on generalisation Salesforce decided to have few components to execute in User mode by default and Few in System mode by default to change the default and have it our way we use With Sharing or Without Sharing Key words.
All Answers
To Simplify the explanation further : there are two modes in which apex executes - User Mode and System Mode .
Where the code that Executes in User mode will keep the Sharing Model in mind and access only those records and objects which are available to the user.
Where as the System mode executes irrespective of Sharing model.
Based on generalisation Salesforce decided to have few components to execute in User mode by default and Few in System mode by default to change the default and have it our way we use With Sharing or Without Sharing Key words.
Reply back if you have anything specific.
Regards,
Ashish
what is the difference between with sharing and without sharing keywords in apex?
https://www.sfdc-lightning.com/2018/11/with-sharing-and-without-sharing-in.html