Using this type of ad will help drive a targeted group of people to attend your event. These will show up in the News Feed of the specific audience you've chosen. Events are a big part of most businesses, but getting people to attend even a small event, can be tricky. Promoting your event to a targeted specific audience on Facebook can help drive the right kind of attendees.
You also have the option to select a Custom Audience -- this allows you to target people on Facebook who are in your company's contact database, visited a page on your website that has a tracking pixel, or use your app or game. To learn more about how to set up a Custom Audience on Facebook, check out these instructions. (And for more on the specifics of these criteria, visit this Facebook targeting resource.) How to prepare and market using Facebook Ads