As the name already suggests this editing view is going to be simple with all the most necessary fields. So you could quickly update the most frequently used values. For that you simply need to just click on a pen icon on the product that you'd like to edit.
After that you will be prompted with a pop-up, where you can quickly edit product price, name, description etc. After the edits have been made, just simply click on save.
As the name suggests this is going to be a little bit more advanced. Advanced view is used to access all the product meta-data that you might usually not see or fields that are not accessible via "Simple view". In advanced view you can easily add, edit or delete attributes, images etc. To get to the advanced editing view, you need to follow the steps from "Simple edit" and click on "Advanced" once the pop-up opens.
And you will be prompted with all the meta-data fields that the product has. Some fields might be gray and that is due to the fact that that field is meant for "read-only" purposes. After you've made your changes, just simply click on save.