Overlay virtual networks are virtual logical networks constructed on top of an existing network using network virtualization technologies45. They decouple network services from the physical networking and interconnection technologies on the underlay network45. Two true statements about overlay virtual networks are:

• Overlay virtual networks work well on an IP spine-and-leaf topology6. They can be created over underlay networks using network virtualization technologies4.
• Overlay virtual networks allow both Layer 2 and Layer 3 communication65. They can serve not only different services (such as multiple departments) of the same tenant but also different tenants4. References from Juniper site: Microsoft Learn, Huawei IP Encyclopedia, Network Insight

Containers perform abstraction at the application layer12. They are executable units of software in which application code is packaged along with its libraries and dependencies, in common ways so that the code can be run anywhere—whether it be on desktop, traditional IT or the cloud12.

The two primary ways used to manage objects by kubectl are imperative commands and declarative object configuration10. Imperative commands operate directly on live objects in a cluster. The user provides operations to the kubectl command as arguments or flags10. Declarative object configuration specifies the operation (create, replace, etc.), optional flags and at least one file name. The file specified must contain a full definition of the object in YAML or JSON format10.