Office 365 is a cloud services platform that offers familiar Microsoft products like Word, Excel, PowerPoint, and OneDrive (along with other productivity services) either online or on-premises via a subscription plan.
Microsoft 365 is a all-in-one bundle that includes the Office 365 suite, Windows 10 Pro and Enterprise Mobility+Security for a complete, interconnected experience.
Microsoft Azure is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through Microsoft-managed data centers.
Amazon Web Services
Amazon Web Services (AWS) is a subsidiary of Amazon that provides on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis.
Google Cloud Platform, offered by Google, is a suite of cloud computing services that runs on the same infrastructure that Google uses internally for its end-user products, such as Google Search and YouTube.
Private Cloud / Hybrid Cloud
A Private Cloud, as the name suggests, is a cloud infrastructure that is meant for use exclusively by a single organization. The cloud is then owned, managed and operated exclusively by the organization or by a third-party vendor or both together.
The Hybrid Cloud uses a combination of at least one Private and one Public Cloud.