A perfect example would be a photographers portfolio website. They may have different pages for different types of photos such as nature, cars even maybe something small such as street signs. Having a car page would mean, no images of nature should be in the gallery of the car page, unless the photo over laps each category. Then the photo could be an exception.
Just like the WIX editor, you can change and customise anything on your site. You will probably find some changes you would like to make and ADI is perfect as it allows you too. The only difference is, if you want to change a part of the site, all the information shows in a column to the left of the screen. This can make your use of the ADI much quicker and get your website published as quick as a possible.