How is resource isolation implemented in container technologies?

Resource isolation in container technologies is implemented using mechanisms of the operating system kernel, such as cgroups (control groups) and namespaces.

• Namespaces isolate resource visibility: processes in a container see only their own processes, network interfaces, file systems, etc. This creates an effect of a separate space for each container.
• Cgroups limit and control the usage of resources (CPU, memory, disk, network) by each container, so that one container cannot exhaust the host's resources.

Thus, containers operate as isolated environments, using a shared OS but with access and resource restrictions, ensuring security and predictability of operation.