Instruction:
Please extract definitions of important domain concepts in the given text below. Please provide the response in the below format: 
Concept, has_definition, Concept. 

Example: 
Intranet, has_defintion, set of networks that are under the control of a single administrative entity
E2EE, has_definition, digital communications paradigm of uninterrupted protection of data traveling between two communicating parties.
LAN, has_definition, connects computers and devices in a limited geographical area

Text:
Network delay is a design and performance characteristic of a telecommunications network. It specifies the latency for a bit of data to travel across the network from one communication endpoint to another. It is typically measured in multiples or fractions of a second. Delay may differ slightly, depending on the location of the specific pair of communicating endpoints.

Network Security consists of provisions and policies adopted by the network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of the computer network and its network-accessible resources. Network security is the authorization of access to data in a network, which is controlled by the network administrator. Users are assigned an ID and password that allows them access to information and programs within their authority.  Network security is used on a variety of computer networks, both public and private, to secure daily transactions and communications among businesses, government agencies, and individuals.