The namespace functionality allows for partitioning of kernel resources, such that one set of processes sees one set of resources, while another set of processes sees a different set of resources. The feature works by having the same namespace for these resources in the various sets of processes, but having those names refer to distinct resources. Examples of resource names that can exist in multiple spaces (so that the named resources will be partitioned) are process IDs, hostnames, user IDs, filenames, and some names associated with network access and inter-process communication.

When a Linux system boots; that is, only one namespace is created. Processes and resources will join the same namespace, until a different namespace is created, resources assigned to it, and processes join it.