The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.

Important: Although there is a SUM function, there is no SUBTRACT function. Instead, use the minus (-) operator in a formula; for example, =8-3+2-4+12. Or, you can use a minus sign to convert a number to its negative value in the SUM function; for example, the formula =SUM(12,5,-3,8,-4) uses the SUM function to add 12, 5, subtract 3, add 8, and subtract 4, in that order.

Cloud term उन servers (group of servers in single cluster) के लिए refer की जाती है जो की public or private use के लिए internet पर available होते है | ये internet से connected servers clients को अलग अलग charges पर (कुछ services free भी होती है) software or storage services provide करते है | Cloud based service कई तरह की हो सकती है जैसे की वेब एंड फाइल होस्टिंग, फाइल शेयरिंग या फिर सॉफ्टवेयर distribution आदि |