Spam filtering is a technology used to identify and block unwanted or unsolicited emails, commonly known as spam. These filters analyze incoming messages based on various criteria, such as keywords, sender reputation, and user behavior. By doing so, they help keep inboxes clean and reduce the risk of phishing attacks and malware. There are different types of spam filters, including blacklist filters that block known spam sources and whitelist filters that allow only approved senders. Many email services, like Gmail and Outlook, incorporate spam filtering to enhance user experience and security, ensuring that important messages are not lost among junk mail.