Composable Commerce is an ecommerce architecture approach where a business builds its digital commerce stack by assembling best-of-breed components—such as storefront, search, checkout, CMS, PIM, OMS, payments, and personalization—and connecting them through APIs.
GraphQL is an API query language and runtime that lets a client (for example, a storefront, mobile app, or any frontend) request exactly the data it needs—no more and no less.
MACH Architecture is a modern ecommerce and digital experience approach based on four principles: Microservices, API-first, Cloud-native, and Headless.
Microservices architecture is a way of building software where a large system is split into many small, independent services, each responsible for a single business capability.