Security principles & access control concepts, identifying & mitigating common security threats and vulnerabilities, network security fundamentals (ports, protocols, secure network design, firewalls, IDS/IPS), security operations & incident response (monitoring, detection, escalation, response steps), identity and access management (authentication, authorization, account lifecycle), risk management & governance (policies, frameworks, compliance, business continuity, disaster recovery), cryptography basics (encryption, hashing, certificates, PKI), secure software development concepts, security awareness & end-user training.