What does "process entry: actually do?

Hi,

I;ve watched teh video tutorial on ‘client data’, they briefly mention doing this part never mention why really. I can’t find any documentation on the website(seems rather strange not to havedocumentation available).

So was does this actually do? Why do we need to process an entry?

https://wordpress.org/plugins/easy-contact-forms/