issues with wp-cron.php

I received an email from my hosting provider, stating that my site is causing other sites on my server to run slow because the wp-cron file is coming up to much and if it continues my hosting will be suspended. Can anybody tell me what the wp-cron.php file is, what it does, and possibly how I can resolve this issue? If needed I can include a copy of the email that was sent. It’s a pretty general email but, let me know..

The site is notsomotivational.com

Thanks.