The differences between "Avis Option" tab and "Shopify Option" tab

The "Avis Option" tab is where you can create unlimited custom options for your product, outside the Shopify limit. This part includes features and option types that Shopify doesn't have such as text, pop-up, file upload, add charge, etc.

The "Shopify Option" tab is where you can customize the already there Shopify Option created when you make the product, which is the Shopify variant. There are 6 styles you can choose from: Button, Dropdown menu, Color or image swatch, Swatch in button, Swatch in dropdown menu and Swatch with price.