RAM is used to share resources between AWS accounts
Product needs to support RAM
The resource is shared with Principals. A Principal can be an AWS Account, an OU or an entire Org
Shared resources become natively availabl i.e. they are visible in the Principal's AWS console as well as in aws command line for them
No cost for RAM
AZ names are rotated. i.e. what is AZ1 in account A1 may not be AZ1 in A2
Other than AZ name each AZ has an AZ ID. This ID is consistent across all accounts
The account that creates the sharing is called Owner Account
IF the receiving account is in the same Organization as the Owner Account, then the sharing is accepted automatically
IF account is in a different organization or does not belong to any organization then they will have to accept the sharing invite for it to get enabled
With Shared Services VPC, the participating accounts can use the vpc and subnet. But they can not modify them
Participating accounts can provision their own resources (e.g. EC2) in the shared service VPC. The resources provisioned by partitipating accounts are still owned by them