Container fundamentals: Docker, images, registries, namespaces

Container Building Blocks

Containers are isolated execution environments that package an application with all its dependencies into a single portable unit. Unlike virtual machines, containers do not include a guest operating system. Instead, they leverage Linux kernel features including namespaces for isolation and cgroups for resource control. A container image is a read-only template built in layers, where each layer represents a filesystem change. The OCI standard defines image format and runtime specifications, ensuring interoperability across different container runtimes like containerd and CRI-O used in telecom…