Spam is unwanted messages sent to many people at once, usually trying to sell something, trick someone, or just clog up inboxes. Today it mostly describes junk email that floods your inbox: ads for products you didn't ask for, fake prize notifications, or messages from people you don't know.

Email spam is like having someone stuff your mailbox with hundreds of flyers every day for things you'll never want. Most email programs have spam filters that automatically catch these messages and keep them out of your main inbox, sorting them into a special spam folder instead.

People also use spam as a verb: someone might spam a chat by posting the same message over and over, or spam a forum with advertisements. Social media platforms work hard to block spam accounts that send friend requests to thousands of strangers or post repetitive comments everywhere.

People try to avoid spam by being careful about where they share their email address online and by not clicking links in suspicious messages. Real companies should not ask you to send money or share passwords through random emails. When something looks like spam, it probably is, and many people just delete it and move on.