What method does Docker utilize for isolating applications?

Docker employs the method of containerization to isolate applications. In the context of software deployment and execution, containerization involves encapsulating an application along with its dependencies, libraries, and configurations into a single unit known as a container. This allows each application to run in its own environment while sharing the same operating system kernel, leading to efficient resource usage and quick startup times.

Containerization provides several advantages, including consistency across various environments (development, testing, production), improved security through isolation, and simpler scalability. Each container operates independently, which means that changes in one do not affect others. This enables developers to ensure that applications run the same way across different cloud platforms or on-premises systems, minimizing the "it works on my machine" problem.

In contrast, virtualization, while also a method for isolation, typically involves creating full virtual machines, each with its own operating system. This can lead to higher overhead in terms of resource usage and longer startup times. Segmentation and separation may describe various concepts in networking or process management but do not specifically refer to the technique Docker utilizes for application isolation. Therefore, containerization is the definitive method that encapsulates the essence and functionality of Docker's approach.