Network security has changed a lot over the past few years. There are a lot of data monitoring and analysing these days in order to detect certain activities of the data and systems. During the past, network at that time was very small and many users are familiar with each other in their professional careers which limited the risk and threat. There were several violations of security during this time. Including "hacking." But a few actions were taken to limit the damage. Today there are many ways of securing a network. Password authentication, anti-virus protections, firewall and system checking devices are simply a couple of the things that could ensure your system. It also limits the activity that companies can do because of the added security to the network and also prevent viruses or programs that do not meet the security requirements. This essay will elaborate more on network security and how to manage it. In the current world of global data communications, Internet connections and software development are highly dependent on security. Security is becoming more of an issue in the networking world. System Security is currently a fringe necessity in light of the fact that worldwide figuring is frail. As the information goes from source to destination on the Web it may pass through a few different focuses along the way, giving different clients the chance to assume control, and even trade off it. Network security can be used in many different scenarios and there are many types of network security software. For example, firewall is one of the software that company uses to protect its data and network from any viruses, worms or any unauthorized programs. There are different types of firewall applications besides just firewall. Few of them are, application gateways and packet filtering.Application portals otherwise called intermediary passages, are comprised of defence that runs unique programming that goes about as a proxy server. This software runs with the application layer in the OSI (Open system interconnection) ISO (International standardization organization) model. Clients that are behind the firewall must be prioritized in order to use internet services. Application gateway is viewed the most secure, because they don't allow anything to pass by default Matt.C (1997). Packet Filtering is a procedure where routers have access control list (ACL) turn on. A router will pass all default traffic without verifying anything. Using ACL (Access Control List) method, it will follow the security policy according to the user security configurations. There is less overtop in packet filtering than with application layer, on the grounds that the gimmick of access control is performed at a lower ISO/OSI layer. Because of the lower high up and that packet filtering is finished with switches, which are specific machines that are progressed for undertakings identified with systems administration, and parcel separating door is much quicker than application layer. (Matt, 1997). The security administration for diverse systems shifts relying upon the circumstances. The level of security administration for a family unit would be lower than the level of security needed by a fort