Perform Internet research to review at least 3 contemporary operating systems (OS). Choose at least one Mac and one Windows OS, along with one of the following OS kinds: (a) *NIX family OS, (b) a mainframe OS, (c) embedded OS, or (d) real-time OS. What do you think is the role of OS in contemporary computer systems? How does that role differ for different types of computers? Describe your answer. Make sure to write the resources you utilized to support your findings.