Region (in Power Platform) maps to Geography (in Azure). The Regions in Azure are for e.g. East US, West US, and the Geography is United States, however on the Power Platform Region is displayed as United States.

On PPAC what's displayed under Region is actually a Geography as per Azure, so while Environment provisioning there's no way a PP can be setup by explicitly selecting East US.

Interestingly the Geographical availability of D365 as listed at Product Availability by Geography | Dynamics 365 (microsoft.com) shows a distinction between Geography and Region.

The terminology difference also has other potential issues as posted (in 2020) at https://experience.dynamics.com/ideas/idea/?ideaid=40985e4d-250e-eb11-b5d9-0003ff68ded8.

What is the plan to align the terminology difference between PP and Azure?

As a side note, the Idea Description area should allow images to be inserted.