What is the difference between TCP and UDP?

TCP is a connection oriented protocol, which means that everytime a packet is sent say from host A to B, we will get an acknowledgement. Whereas UDP on the other hand, is a connection less protocol.

Where will it be used : TCP -> Say you have a file transfer and you need to ensure that the file reaches intact, and time is not a factor, in such a case we can use TCP.

UDP-> Media Streaming, question is say you are watching a movie…would you prefer that your movie comes..perfectly….but u need to wait a long time before you see the next frame ?..or would you prefer the movie to keep streaming…Yes…The second option is definely better….This is when we need UDP

What is ARP/RARP?

ARP: Stands for Address Resolution Protocol…whenever a request is sent by a node on one network to the node on another network the Physical address(MAC) is required and for this the IP address need to be flow over the network..whenver a router with that network (IP) gets the msg. the required MAC address is sent through the network this process of converting the IP address to MAC address is Called ARP..and the reverse thats the convertion of the Mac address to the IP address is called RARP ( Reverse Address Resolution Protocol)