In information technology, a network is a series of places called nodes that are interconnected by some kind of communication. Networks can interconnect with other networks and contain subnetworks.
Simple Mail Transfer Protocol – SMTP is used as an internet standard for the transmission of e-mails in case of an IP (internet protocol network) network.
SWITCH
A switch can be used in the local area network (LAN) as a multi-port bridge device. Under discussion mechanism works at the Layer2 (data-link) of the OSI reference model.
NIC (network interface card) is a gadget that works as a bridge between computers. In other words, this piece of equipment is used to join together multiple computer systems in a local area network (LAN).
What is LAN? Connecting two PCs for the purpose of sharing data and attached peripherals that mean, you have established a LAN (local area network). But the figure of computers connected within a LAN can be fixed and can be to a limit of several hundreds computer systems.