Shopify Markets compatibility refers to a theme, app, or feature’s ability to work seamlessly with Shopify Markets, enabling merchants to sell to customers in multiple countries and regions. Compatible themes and apps support features such as localized currencies, languages, pricing, domains, taxes, and shipping options, ensuring customers receive a tailored shopping experience based on their location. This helps businesses expand internationally while providing a consistent and user-friendly storefront.

Custom CSS (Cascading Style Sheets) is additional code used to modify the visual appearance of a Shopify store beyond the default theme settings. It allows merchants and developers to customize colors, fonts, spacing, layouts, buttons, product cards, and other design elements without changing the core theme files. Properly implemented custom CSS helps create a unique brand experience while maintaining a consistent and responsive storefront design.

Headless Shopify is an architecture where the frontend storefront (the customer-facing website) is separated from Shopify’s backend commerce system. Instead of using a traditional Shopify theme, developers can build a custom frontend using technologies like Shopify Hydrogen (React framework) and connect it to Shopify through APIs.

Headless Shopify allows brands to create highly customized, fast, and flexible shopping experiences across websites, mobile apps, kiosks, and other digital channels while still using Shopify for products, inventory, checkout, payments, and order management.