介绍了计算机网络安全问题所涉及的各方面内容。从全局角度介绍计算机网络安全的概念、体系结构和模型，讨论了网络安全主要包含的内容和研究方向，介绍当前网络安全的主要产品。

The content of computer network security is discussed in this article Firstly, the concept, system and structure and model of computer network security are given. Then the main content and correlative researching aspect are included. In the end, the main product is introduced.