EXMAGE

Hello, I want to try the EXMAGE – WordPress Image Links plugin, only I still don’t understand the concept well and I have these questions:
a) I am using ALD – Aliexpress Dropshipping and Fulfillment for WooCommerce and with this plugin I import the products and their images, so how are the images stored elsewhere?
b) Where are the images physically stored if I only assign the link on my website?
b) The site is not slowed down by not physically having the images?

Regards

Víctor