Server software licenses are licenses assigned to operating systems Microsoft has produced for servers. Moving existing servers and applications to a virtual environment often results in additional licensing costs. Therefore, it causes changing licensing conditions for operating systems and application software. Therefore, in the world of server licenses, there are two licensing models: licensing by number of processors and licensing models by number of cores. Software for commercial customers requires legal licenses even for open-source solutions. But this is not always easy in large software companies. Because applications and operating systems run on servers with multi-core processors, it is sometimes unclear whether the machine or the core is important. The situation becomes confusing when the software is to be installed in virtualized environments. In addition, software giant Microsoft has created a clear regulation on this issue. License costs depend on the number of CPUs on the server. There are exceptions in some cases. That’s why you need to do per-server licensing on Windows server 2008.