What best describes an approach where a single application consists of many loosely coupled components?

The approach where a single application consists of many loosely coupled components is best described by microservices architecture. This architecture style structures an application as a collection of small, independent services that can communicate over well-defined APIs. Each service is designed to be self-contained, allowing for independent development, deployment, scaling, and maintenance. This modularity provides significant flexibility and allows teams to use different technologies for different services, enhancing agility and speeding up the development process.

In microservices architecture, the focus is on how services interact and are organized to deliver complex functionalities efficiently. This decomposed architecture contrasts with monolithic applications, where everything is tightly integrated, making it difficult to adapt or scale specific parts of the application without affecting the entire system. By embracing microservices, organizations can better align development with business needs and respond rapidly to changes in the market or technology landscape.

While application modernization refers to updating and improving existing software applications, it doesn’t specifically address the concept of loosely coupled components like microservices do. Hybrid multicloud involves utilizing multiple cloud services seamlessly but does not inherently describe the architecture of an application itself. Finally, virtualization relates to creating virtual versions of hardware or software and doesn't specifically describe the architecture of an application made up of discrete, interactively functional components.