Namespace OS
In plain terms
A Linux feature isolating system resources for processes.
Going deeper
Namespaces partition kernel resources, process IDs, networking, mounts, so processes see isolated views, the foundation of containers. They create isolated environments.
Under the hood
Combined with cgroups, they enable containerization; types include PID, network, mount, and user namespaces.
Examples
Containers, Docker isolation, PID/network namespaces, sandboxing.
Think of it like...
Like giving each tenant their own private view of the building's facilities.