What is spoofing?

In the context of computing, spoofing can relate to a number of things, with nearly all concerning forgery and malicious intent.

IP address spoofing involves the creation of IP packets with a forged IP address in order to conceal the sender's identity or to impersonate another computer system. IP spoofing is most often used in denial-of-service attacks because it can hide the true source of attack as well as making filtering more difficult.