What is a "Catch All" email address?
A "Catch All" email address is one that you can set up to receive any email sent to any address on your domain. For example, if you only have email@example.com set up, but you have it set as your catch all email, then you will also receive emails to firstname.lastname@example.org, email@example.com, as well as any typos.
Setting up a catch all email is a good idea to ensure that you don't miss any emails sent to your domain. It is especially good if your name is something that is often misspelled.