Bridge
A node connected to two or more administratively indistinguishable but physically distinct subnets, that automatically forwards datagrams when necessary, but whose existence is not known to other hosts. Also called a "software repeater".
Gateway
A node connected to two or more administratively distinct networks and/or subnets, to which hosts send datagrams to be forwarded.
Host Field
The bit field in an Internet address used for denoting a specific host.
Internet
The collection of connected networks using the IP protocol.
Local Address
The rest field of the Internet address (as defined in [3]).
Network
A single Internet network (which may or may not be divided into subnets).
Network Number
The network field of the Internet address.
Subnet
One or more physical networks forming a subset of an Internet network. A subnet is explicitly identified in the Internet address.
Subnet Field
The bit field in an Internet address denoting the subnet number. The bits making up this field are not necessarily contiguous in the address.
Subnet Number
A number identifying a subnet within a network.