With the rapid expansion of digital infrastructure and the growing reliance on technologies such as the Internet of Things (IoT) and cloud computing, network security has become essential for protecting data and ensuring the continuity of digital services amid increasingly sophisticated cyber threats. Fundamental Pillars of Network Security Network security is based on three core principles known as the CIA Triad: Confidentiality, which protects data from unauthorized access through encryption techniques; Integrity, which ensures data accuracy and prevents unauthorized modification; and Availability, which guarantees continuous access to systems and resources while mitigating denial-of-service attacks. Major Cybersecurity Threats Networks face several threats, including Man-in-the-Middle (MitM) attacks, which intercept communications to steal or manipulate data; malware, including ransomware and spyware; and Distributed Denial-of-Service (DDoS) attacks, which aim to disrupt services and render them unavailable. Modern Security Strategies Addressing these threats requires advanced security strategies, including Zero Trust Architecture, which relies on continuous verification of users and devices; Intrusion Detection and Prevention Systems (IDS/IPS), which monitor network traffic and identify suspicious activities; and the use of Artificial Intelligence (AI) and Machine Learning (ML) to analyze abnormal behavior and predict potential cyberattacks. Conclusion Network security is an ongoing process that requires continuous updates to security policies and the development of protection mechanisms in response to evolving digital threats. These efforts are essential for maintaining data confidentiality, integrity, and availability while strengthening cyber resilience against emerging risks.