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.
The basics of SEO are very important to comply with. They help search engines understand your website and what it is about. Using algorithms search engines will then rank your site appropriately to specific searches. Ideally you want your site to be on the first page of a search, which can be very hard. Generally the basics of SEO does not achieve first page ranking as it requires a bit of work and effort to do so.