What do you understand by network security ? Why is it considered very important ?

Network security refers to making sure that only legal or authorized users and programs gain access to information resources like databases. Also, certain control mechanisms are setup to ensure that properly authenticated users get access only to those resources that they are entitled to use.

Network security is very important because data travels through a network. Protection of data and its secure transmission is only possible if methods are employed to secure the network from various threats like physical/software security holes, inconsistent usage holes, hacking, cracking, etc.