The primary focus of a network administrator is to manage, maintain, and secure computer networks. This includes overseeing network performance, ensuring connectivity, implementing security measures, and troubleshooting any issues that arise. They are responsible for configuring hardware and software, managing user access, and ensuring compliance with security standards. Additionally, a network administrator may work on network upgrades, monitor network traffic, and develop policies to improve network efficiency and reliability. Overall, their role is vital in ensuring that organizational communication and data flow seamlessly, thereby enhancing productivity.