JavaScript HTML DOM EventListener | Add an Event Handler to an Element

JavaScript HTML DOM EventListener,
What is eventListener in JavaScript?,
How you define events in HTML DOM?,
How do you add an eventListener to a function?,
How do I get rid of addEventListener?,
How can you assign event handler to some HTML element?,
How do you add an event listener to a group of elements?,
How will you add a click handler?,
How do you add an event listener in inspect element?