For some content platforms, the word “theme” means a limited degree of control. It evokes the idea of selecting from a few predefined choices, perhaps picking a color scheme or replacing some images.
Shopify themes are more than that; they give storeowners complete control over every aspect of the frontend of their sites, including HTML, stylesheets, and scripts. This, I believe, is one of Shopify’s greatest strengths. It’s why it can be suitable for solo entrepreneurs starting their first business while at the same time supporting Fortune 500 companies.