How to check customer is authenticated in Magento 2?

Customer Authentication using Magento 2 to check customer types like its a guest user or login user.

There are many occasions when you need to check customer authentic status and based on the login customer only you need to show a specific page otherwise redirect it to the login page.

Verify the customer has valid authentication using \Magento\Customer\Model\Session Class. add the Customer Session class to the __construct() method of your Controller.

Using this approach, validate the customer authenticate status for the login user.