Broken pages or 404 status errors are pages requested by the browser which were not found by the server.
All websites have some pages returning the 404 status error, this is why Google recommends to check your website on a regular basis.
Having users sent to 404 status pages will most likely have a negative impact on the user experience. Even more so on your budget if that traffic is from paid sources.
With the help of this report you will quickly find which sources bring the most traffic to broken pages and make the necessary fixes.