The term node is used in networks as a point of interconnection of transmission paths. However, the term node is also used in computer science and web terminology. In computer science, a node is part of the tree structure that represents any object. And in web terminology, a node is a uniquely identifiable unit of information that cannot be further subdivided. Such a node can be an HTML document and can be uniquely assigned by the Internet address.
In network technology, a node or network node is a device that performs switching functions, but also operates at the network edge as an interworking unit. A node can be a controller, node computer, terminal, printer, disk drive, minicomputer, gateway, or other device. A node can multiply, split, and statistically allocate data channels, as well as switch data transmission channelsusing dynamic allocation.
Depending on the network configuration, the switching nodes in thePSTN and ISDN are called exchanges, in the Internet they are called gateways or routers, in Internet service providers (ISPs) they are called Internet nodes or Internet exchange points(IXPs), in Arpanet they are called interface message processors (IMPs), in Open Systems Interconnection (OSIs) they are called intermediate systems (ISs) or relays, and in X.25 networks they are called data packet exchanges(PSEs).
A node is a source and a sink for data. It is usually implemented by the Data Terminal Equipment( DTE) and/or the Data Transmission Equipment( DCE). The node is known to the DFV access program by a symbolic name. For example, in the SNA architecture, a central node is a Physical Unit( PU) with Virtual Telecommunications Access Method(VTAM) and Telecommunication Access Method ( TCAM) and application programs, a Local Node corresponds to a local IBM 3705-II, a Remote Node corresponds to a remote IBM 3705-II, and a Cluster Controller or Terminal Node may be an IBM 3790, 3770, or 3270.
Nodes perform independent control functions and, as switching devices, support data transmission from independently operating terminals to a remote data processing facility.