Unicast
Unicast is a type of transmission in which information is sent from only one sender to only one receiver. In another words, Unicast transmission is between one-to-one nodes (involving two nodes only).
Examples of Unicast transmission are http, smtp, telnet, ssh, pop3 where the request for information is directed from one sender to only one receiver [...]
Header refers to supplemental data placed at the beginning of a block of data being stored or transmitted, which contain information for the handling of the data block.
In data transmission, the data following the header are sometimes called the payload or body. It is vital that header composition follow a clear and unambiguous specification or [...]
A packet is the fundamental unit of information carriage in all modern computer networks. The term datagram is sometimes also used, and in some contexts its meaning is subtly different from packet.
A packet consists of a header, which contains the information needed to get the packet from the source to the destination, and a data [...]
Before you start to get any deeper into the computer networking, it is important that you have a sound understanding of some of the basic elements of a network as mentioned below. Ask yourself what these are before you click on them.
Packet
Header
Unicast, Broadcast and Multicast
Broadcast Domain
Collision Domain