This document summarizes a research paper that classifies different types of networks and discusses their associated security issues. It categorizes networks based on size (LAN, MAN, WAN), design (peer-to-peer, client-server, standalone), layering (layered, non-layered), and provides examples such as Ethernet, Wi-Fi, VPNs. It also discusses common security threats for different network types like viruses, denial of service attacks, and evaluates security measures including encryption, firewalls, access control. The paper aims to provide a comprehensive classification of networks and analyze how security needs vary depending on the network and software development stages.