A VoIP phone or IP phone uses voice over IP technologies for placing and
transmitting telephone calls over an IP network, such as the Internet, instead of the
traditional public switched telephone network (PSTN). 
Digital IP-based telephone service uses control protocols such as the Session Initiation
Protocol (SIP), Skinny Client Control Protocol (SCCP) or various other proprietary protocols. 
An Internet Protocol camera, or IP camera, is a type of digital video camera that receives
control data and sends image data via the Internet. They are commonly used for surveillance.
Unlike analog closed-circuit television (CCTV) cameras, they require no local recording device,
but only a local area network. Most IP cameras are webcams, but the term IP
camera or netcam usually applies only to those used for surveillance that can be directly
accessed over a network connection.
Some IP cameras require support of a central network video recorder (NVR) to handle the
recording, video and alarm management. Others are able to operate in a decentralized manner
with no NVR needed, as the camera is able to record directly to any local or remote storage
media. The first centralized IP camera was Axis Neteye 200, released in 1996 by Axis
A computer network is a digital telecommunications network which allows nodes to share
resources. In computer networks, computing devices exchange data with each other using
connections (data links) between nodes. These data links are established over cable media such
as wires or optic cables, or wireless media such as Wi-Fi.
Network computer devices that originate, route and terminate the data are called network
nodes.  Nodes are generally identified by network addresses, and can include hosts such
as personal computers, phones, and servers, as well as networking hardware such as routers
and switches. Two such devices can be said to be networked together when one device is able
to exchange information with the other device, whether or not they have a direct connection to
each other. In most cases, application-specific communications protocols are layered (i.e. carried
as payload) over other more general communications protocols. This formidable collection
of information technology requires skilled network management to keep it all running reliably.
Computer networks support an enormous number of applications and services such as access to
the World Wide Web, digital video, digital audio, shared use of application and storage servers,
printers, and fax machines, and use of email and instant messaging applications as well as many
others. Computer networks differ in the transmission medium used to carry their
signals, communications protocols to organize network traffic, the network’s size, topology, traffic
controlmechanism and organizational intent. The best-known computer network is the Internet.