What should I study for cybersecurity?

Cybersecurity requires a layered knowledge base. Start with networking fundamentals because most attacks traverse networks. Learn TCP/IP, the OSI model, DNS, DHCP, firewalls, and packet analysis. According to CyberSeek (2024), network security is the most commonly listed skill in entry-level cybersecurity job postings.

Next, build operating system skills. You need working knowledge of both Linux and Windows. Learn the command line for each, understand file permissions, user management, and system logging. Most SOC environments use Linux-based tools and monitor Windows endpoints. The NICE Framework (NIST SP 800-181, 2020) lists operating system knowledge as a foundational requirement across nearly all cybersecurity work roles.

Then study core security concepts: the CIA triad (confidentiality, integrity, availability), authentication vs. authorization, symmetric and asymmetric encryption, hashing, digital certificates, and common attack types (phishing, malware, SQL injection, XSS). The CompTIA Security+ exam (SY0-701) covers all of these topics and costs $404 as of April 2026.

Finally, practice with real tools. Set up Wireshark for packet capture, use Nmap for network scanning, and learn a SIEM platform like Splunk or Elastic. Hands-on experience separates candidates who interview well from those who only have book knowledge. DecipherU's career path guides map specific study topics to each cybersecurity role so you know exactly what to prioritize.