The brief
Docker Sandboxes are microVMs with their own Linux kernel, filesystem, network, and Docker Engine, whereas containers are isolated processes that share the host kernel. This fundamental difference affects their use cases, with containers suitable for packaged applications, CI jobs, and short-lived execution, and Docker Sandboxes fitting autonomous agents that require sudo, a private Docker Engine, long-lived state, and host-enforced network and credential controls.
The key distinction between the two lies in their isolation boundaries. Containers share the host kernel, making them less secure for autonomous agents that can act on unvetted instructions and accumulate state over hours. In contrast, Docker Sandboxes provide a dedicated microVM with its own kernel, ensuring a stronger boundary between the agent and the host machine. This allows for better containment, control, and choice in managing autonomous coding agents.