Free Way to Delete Documents and Data on iPhone?

What is documents and data on iPhone? Whatsapp itself only 30MB but the "Documents and Data" takes up 4.5GB?! So, how to delete documents and data from iPhone? Tutorial: https://www.imyfone.com/iphone-space-saver/what-is-documents-and-data-on-iphone/ Free Download Now: https://www.imyfone.com/iphone-data-eraser/?utm_medium=video-o&utm_source=youtube_imyfone-o&utm_campaign=UP&utm_term=161009,TzkH30nT_m4