It's possible to send to your site images that are on your hard drive, creating your personal archive of images that is organizable in folders and sub-folders (the same method used to organize the pages of your site in sections and sub-sections).

Go to the image folder (or a sub-folder you created before) and click on the button (add image) located on the bar.

If you have the address (url) of an image you can use that directly.