Why jquery is not preferred in Angularjs

Hi I am learning Angularjs. when moving to the design side, Bootstrap is one of the options for developing a web application using Angular. While searching Angular with Bootstrap, I found an article on ng-bootstrap and they said they don't depend on jquery. can anyone please explain what is the main idea behind Angular. I have searched through the internet, I could not find the correct answer to my question. can someone help me.