The old question of Windows versus Linux is one that most customers have to agree on at some point. However, for any cloud deployment of size, most likely there will be a mixture of both Windows and Linux, with different versions and flavors of each. Therefore, it's important to know which versions are needed and which are offered by the cloud vendor. Typically, the cloud vendor will have many different flavors of each operating system; some will have an associated licensing cost, others will be free to use. The price of the operating system can add up to be a significant portion of the bill, so trying to minimize their use, or using those that are free to use, is recommended for customers who are going fully cloud native.