Describe the concept of event handling in JavaScript and provide an example of anevent and its associated event handler.

Event handling in JavaScript is a process that involves two main components: the event and the event handler.

1. Event: An event in JavaScript is an action or occurrence that happens in the system you are programming, which the system tells you about so you can respond to it in some way if desired. For example, this could be a user clicking a button, a page finishing loading, or an error being thrown.

2. Event Handler: An event handler is a function that will be performed when a specified event occurs. This function is "called back" (hence the term callback function) when the event it is associated with happens.

Here is an example of an event and its associated event handler in JavaScript:

// This is the event handler
function handleClick() {
  alert('The button was clicked!');
}

// Here we select the button and assign the event handler to the 'click' event
document.getElementById('myButton').addEventListener('click', handleClick);

In this example, the event is a click on the button with the id 'myButton'. The event handler is the function handleClick, which displays an alert saying 'The button was clicked!' when the button is clicked. The addEventListener method is used to assign the handleClick function as the event handler for the 'click' event on the button.