Flooding

Flooding is another act of flooding the network with unnecessary data or garbage data. Network who are victims will experience congestion (saturation) due to bandwidth capacity to service customers away by garbage data.
Flooding is a very terrible thing for the network admin. Most people think just walking in the ICMP flooding, but it is not. Flooding is very varied and can invade a variety of protocols other than ICMP.
1) Sniffing
Sniffing literally sniff out, of course, in this case that diendus is the message (either not yet or already encrypted) in a communication channel. It is common in an insecure public channel. The sniffing could recapitalize the conversation that occurred.
Spoofing
The attacker - for instance C - can impersonate A. Everyone was made to believe that C is A. The attacker tried to convince other parties that there was no wrong done with communication, but communication was done by the deceiver / attacker. For example, if people enter your PIN into the Card Acceptance Device (CAD) - which is really built like the original CAD - of course the fraudsters can get a PIN smartcard owner. Smartcard owner did not know that there has been crime.