For product testing, hardware and operating system-level virtualization helps in reducing the number of physical servers required and time required to set up the servers.
对于产品测试，硬件和操作系统级虚拟化有助于减少需要的物理服务器数量和设置服务器所需的时间。
2
If the operating system can't find the required mapping in the cache, it has to spend some more time completing the translation.
如果操作系统无法在缓存中找到所需的映射，它就必须花更多的时间完成转换。
3
These applications refer to the operating system, run time environments, source control repository, and any other required middleware.