VPN通过一个私有的通道来创建一个安全的私有连接，将远程用户、公司分支机构、公司的业务伙伴等跟企业网连接起来，形成一个扩展的公司企业网(VPN creates a secure private connection through a private channel, connecting the remote user, the company branch, and the business partner of the company with the enterprise network