Spam is an informal term for unsolicited commercial email (UCE), the primary form of Internet spam. It is a neologism formed from the words “spam” and “spiced ham”, since UCE is often disguised to make it seem similar to legitimate email (spiced ham).
Other terms for spam include junk mail, bulk mail, advertising email, or unsolicited commercial email (UCE).
Spam is typically posted in newsgroups or discussion forums with a forged header. The message may be posted repeatedly on different websites. Spammers use botnets to send large volumes of e-mail messages simultaneously, which can disrupt regular operation of targeted computers and networks.
The term also refers to email sent to a user whose address has been collected without the user’s consent and used for marketing purposes (also called “spam”), often to multiple users. It can also refer to the act of sending such emails.