HIDS (Host-Based Intrusion Detection Systems) focuses on monitoring individual hosts, detecting suspicious activities at the host level, such as unauthorized access. NIDS (Network-Based Intrusion Detection Systems), on the other hand, watches network traffic across the entire network to identify broader threats like DDoS attacks and unusual traffic patterns. HIDS is host-centric, while NIDS is network-centric, offering complementary protection for both individual systems and the network as a whole.