Docker and virtual machines (VMs) are both prominent technologies for server and software developer workflows, each offering distinct advantages and challenges depending on the use case. Docker containers have largely replaced VMs as the preferred method for segmentation due to their efficiency in utilizing the host machine's resources, faster startup times, and ease of replicability. In contrast, VMs offer robust security through hypervisor-enforced segmentation and are often easier to conceptualize as they mimic traditional machines. However, Docker's proximity to the host OS can make it more vulnerable to security issues, necessitating careful configuration and monitoring. While containers promote consistency across environments, VMs provide flexibility with multiple configurations and full OS emulation. Furthermore, advancements like Earthly.dev enhance Docker's build and CI/CD processes, making it easier to achieve replicable and efficient development cycles. Ultimately, the choice between Docker and VMs hinges on the specific requirements of the deployment, with both technologies capable of being used in tandem to leverage their respective strengths.