虚拟文件系统的详细描述，大学期间的课程论文-Virtual File System Decription~~~~~~~~~

关于接口和虚拟类的区别，初学者必看。对初学者十分有用。-Difference on the interface and the virtual class, a beginner must see. Very useful for beginners.

虚拟现实技术的应用研究，总结了虚拟现实技术的进展-The study of the application of virtual reality technology, summarizes the progress of virtual reality technology

A dynamic multipoint virtual private network (DMVPN) is a secure network that exchanges data between sites without needing to pass traffic through an organization s headquarter virtual private network (VPN) server or router.VPNs traditionally connect