What feature of Docker allows for rapid scaling of applications?

Lightweight containers are the key feature of Docker that facilitates rapid scaling of applications. Containers utilize a shared kernel with the host operating system, which significantly reduces overhead compared to traditional virtual machines. This lightweight nature allows for faster startup times and more efficient resource utilization, enabling organizations to spin up multiple instances of an application quickly as demand increases.

When the need arises to scale horizontally, Docker can quickly deploy multiple containers without the extensive resource requirements typical of full virtual machines. This agility is crucial in environments where application workloads can fluctuate, allowing businesses to respond swiftly to user demand, thereby ensuring consistent performance and availability.

The other choices, while beneficial in their own right, do not specifically contribute to the rapid scaling of applications in the same way that lightweight containers do. Centralized databases may help with data consistency, but they do not directly enhance the ability to scale applications. Multi-stage builds focus on optimizing the container image size and reducing build times, while integrated networking improves communication between containers but does not inherently affect scaling capabilities.