Let's say you have completed filling the NEET application form and you have the confirmation page. This confirmation page is the proof of your application.Now NTA will go through your application form and check if there is anything that needs to be edited or changed like images. If they find any discrepancy in regards to the images, they will notify you and you can make the changes during the correction window when it opens from January 15th to January 31st. But there will be some information that you might have entered wrong. You can correct it on your own without any notification from NTA. Now let's say you have nothing to be corrected, you can still save the page and take a print out of the confirmation page. Everything will be saved and intact.