Need for security:

The basic objective for providing network security is two fold:
(i) to safeguard assets and (ii) to ensure and maintain the data integrity.
The boundary subsystem is an interface between the potential users of a system and the system itself controls in the boundary subsystem have the following purposes like
(i) to establish the system resources that the users desire to employ and (ii) to restrict the actions undertaken by the users who obtain the system resource to an authorized set.
There are two types of systems security. A physical security is implemented to protect the physical systems assets of an organization like the personnel, hardware, facilities, supplies and documentation. A logical security is intended to control (i) malicious and non-malicious threats to physical security and (ii) malicious threats to logical security itself.