SEO = Search Engine Optimization

SEO is the key in getting your website seen online. High SEO means that your website appears higher in the Google or other search engine results. So it's best if you can do "Search Engine Optimization" to increase the chances of your business or website being found online.

HEre's an article about this, which explores the question of whether some website builders might be better than others for SEO:

www.websitebuilderexpert.com/website-builder-seo-vs-wordpress-seo/