Explanation
+ bandwidth management technique which delays datagrams: shaping+ mechanism to create a scheduler for packets prior to forwarding: policy map+ portion of the IP header used to classify packets: DSCP+ mechanism to apply a QoS policy to an interface: service policy+ tool to enforce rate-limiting on ingress/egress: policing+ portion of the 802.1Q header used to classify packets: CoS To attach a policy map to an input interface, a virtual circuit (VC), an output interface, or a VC that will be used as the service policy for the interface or VC, use the service-policy command in the appropriate configuration mode.
Class of Service (CoS) is a 3 bit field within an Ethernet frame header when we use 802.1q which supports virtual LANs on an Ethernet network. This field specifies a priority value which is between 0 and 63 inclusive which can be used in the Quality of Service (QoS) to differentiate traffic.
The Differentiated Services Code Point (DSCP) is a 6-bit field in the IP header for the classification of packets. Differentiated Services is a technique which is used to classify and manage network traffic and it helps to provide QoS for modern Internet networks. It can provide services to all kinds of networks.
Traffic policing is also known as rate limiting as it propagates bursts. When the traffic rate reaches the configured maximum rate (or committed information rate), excess traffic is dropped (or remarked). The result is an output rate that appears as a saw-tooth with crests and troughs.
Traffic shaping retains excess packets in a queue and then schedules the excess for later transmission over increments of time -> It causes delay.

Explanation
Traffic policing propagates bursts. When the traffic rate reaches the configured maximum rate (or committed information rate), excess traffic is dropped (or remarked). The result is an output rate that appears as a saw-tooth with crests and troughs.
Unlike traffic shaping, traffic policing does not cause delay.
Classification (which includes traffic policing, traffic shaping and queuing techniques) should take place at the network edge. It is recommended that classification occur as close to the source of the traffic as possible.
Also according to this Cisco link, "policing traffic as close to the source as possible".

Explanation
Yet Another Next Generation (YANG) is a language which is only used to describe data models (structure). It is not XML or JSON.

Explanation
From the Tunnel protocol/transport GRE/IP line, we can deduce this tunnel is using the default IPv4 Layer-3 tunnel mode. We can return to this default mode with the tunnel mode gre ip command.