Events tracking lets you record when a user does a certain thing on your site - like visits a special page, signs up for your newsletter, or gets to a certain point in your conversion funnel. By using events tracking you can see which sources of traffic and which entry pages work better for your site and optimise them so you get more signups/conversions etc.
event tracking is very important if you want to track sign-up form,newsletter form.download pdf or any other task.also using event tracking we can see that which event has more popular or more viewable in your website.