In cybersecurity, an adversary is any individual, group, or entity that seeks to compromise the security of computer systems, networks, or data. Adversaries can include hackers, cybercriminals, nation-state actors, or even insiders who exploit vulnerabilities for malicious purposes. Their goals often involve stealing sensitive information, disrupting services, or gaining unauthorized access. Understanding adversary tactics and motivations is crucial for developing effective security measures and defending against cyber threats.