Which technology is primarily used for developing, packaging, and running applications in containers?

The correct answer is Docker. Docker is a platform specifically designed for developing, packaging, and running applications in containers. Containers are lightweight, portable, and can run consistently across various computing environments, making Docker a popular choice for application development and deployment. With Docker, developers can encapsulate their applications along with all the dependencies they need, ensuring that the application runs smoothly regardless of where it is deployed.

Kubernetes, while also integral to the container ecosystem, primarily functions as an orchestration tool for managing containerized applications at scale, rather than being used directly for developing or packaging those applications. Cloud computing refers to the use of networked remote servers to store, manage, and process data, but it is a broader term that encompasses various services and technologies beyond just containerization. Identity as a Service (IDaaS) focuses on providing identity management and authentication services, which does not relate directly to application development or container technology. Therefore, Docker is the key technology specifically utilized for working with containers.