_GroupBy_ takes a label ```key``` as a parameter, places all objects with the same value for that key within a single group. For example ```/groups/host/selector``` groups pods by host. ```/groups/name/selector``` groups pods by name. Groups are hierarchical, for example ```/groups/name/host/selector``` first groups by pod name, and then by host.
Select takes a [label selector](./labels.md) and uses it to filter, so only resources which match that label selector are displayed. For example, ```/groups/host/selector/name=frontend```, shows pods, grouped by host, which have a label with the name `frontend`.
