Network security consists of the policies adopted to prevent and monitor unauthorized access, misuse, alteration of computer network and network resources available. It also requires the authorization to access data in a network that is controlled by administrators. Users' needs to choose or assigned an Id and password and other information that allow them to access information and programs within their authority. Network security covers public and private computer networks, which are utilized in everyday jobs, conducting transactions and connection among business and government agencies and individuals and are involved in organizations, enterprises, and other institution. The most common and simple way to protect a network resource is by assigning it a unique name and a corresponding password.  To read more, read an article by Brendan Ziolo (Head of large enterprise strategy, Nokia): http://networkcomputing.com/net-security/security-starts-network/1250114547