To spoof something is to falsify or otherwise fake information.
The most common use of the term of late is with respect to email. Specifically, the sender of an email – the information that appears in the “From:” line – is easily (and therefore frequently) falsified by spammers. This is known as “From: spoofing”.
As a result, an email’s “From:” line can be:
- Correct: the email is from the source indicated
- Intentionally misleading: in an attempt to fool the recipient into opening the email or acting on its contents, the “From:” line may be spoofed to make it appear that the email came from a contact or other trusted source, when in fact it did not.
- Intentionally random: in an attempt to hide the true source of the email, the “From:” line may indicate a random source that, in fact, had nothing to do with the email.
Spoofing is, of course, not limited to email, or email “From:” information. Various aspects of almost any information can be spoofed for various reasons and with varying degrees of success.