@lars in Chapter 2.4 [az-900-microsoft-azure-fundamentals/learn/cloud-concepts/cloud-services-models] at 0:44 sec on the video, you mentioned about OS, would be worth providing extra clarity here! The reason I ask is because it’s a bit confusing with terms, firstly the "Guest OS" is what anyone using Azure could control when we are talking about VM’s provided as IaaS and secondly I’m not sure if buying "Guest-OS" is correct here as the cost of "Guest OS" is included in the pricing of the azure VM service (selecting SKU’s) while spinning up a VM I belive? I may be wrong but open to learn 🙂
The lesson is explaining the concept of IaaS, which doesn’t include an operating system. On Azure you can choose to have a specific OS pre-configured, and if you already own a license it can also be cheaper.
I hope this helps.