A website event is when a visitor to your website does something, like submits a contact form, makes a purchase or watches a video.
Having great traffic, a strong conversion rate and a nice website is great, but you need to be able to track exactly what visitors to your site are doing. You might have plenty of visitors hitting your contact form but no one is actually contacting you. You then find out that your contact form is going to an email address that you no longer use. Without tracking events on your website you can end up providing some bad service to your customers and by tracking events you can provide your customers with the best service possible.