Network security is a specialist area of networking it consists of the requirements complete in an basic computer network infrastructure, policies implement by the network administrator to protect the network and the network-accessible resources from unauthorized access, and consistent and continuous monitoring and measurement of its effectiveness (or lack) combined together
The network security is providing security at the boundaries of an organization and secure for hackers. Focuses of protection is data resources from malicious software and mistakes generated organization’s people /employees.
Simply Its use for user authentication (may be one factor, two factor and multi-factor authentication. Two factor and multi-factor authentication know as strong factors authentication). Selection of authentication is depends on company‘s policies.
Once authentication , a firewall insist on access policies (eg. which services are allow to users).its totally protect the system from malware.For the privacy purpose use encryption and decryption of any communication.

Security management

Security management is implement in different ways on network .simply its depends on the networks situations.

Small homes

In homes basically use firewall and also any strong Anti virus . When using a wireless connection, use a robust password. Also try to use the strongest security supported by your wireless devices. Assign STATIC IP addresses to network devices and disable ICMP ping on router. use password for all connection . each family member have its own accounts don’t use administrative account.disable the guest account.

Medium businesses

Use strong firewall /unified threat management system , strong Antivirus , internet security software.Also use strong authentication method .in the case of wireless connection use robust password.

Large businesses

To keep away unwanted peoples so use proxy and strong firewall. Get powerful antivirus software and internet security software packages. Also use authentication ,use robust passwords in the case of using wireless connection. When you need monitor the networks. Implement physical security management and specially consider important areas

Schools

Use adjustable firewall, proxy, strong antivirus software packages, internet security software packages. Use wireless connections that lead to firewalls.

Large Governments

To keep away unwanted peoples so use proxy and strong firewall. Get powerful antivirus software and internet security software packages. Use strong encryption. Block all wireless connection except white list authorized wireless connection. make sure the network is invisible to outs