Blacklist
A blacklist is a security mechanism comprising a list of entities, such as IP addresses, URLs, email addresses, or applications, that are denied access or privileges within a system due to being deemed a security risk or unwanted. Blacklisting helps in protecting systems against spam, phishing attacks, malware distribution, and other security threats by blocking potentially harmful communications or transactions. While effective in enhancing security posture, blacklists require regular updates to adapt to evolving threats and ensure legitimate users or resources are not inadvertently blocked.