Question

According to their website, for S3:

Amazon S3 standard storage is designed to provide 99.999999999% durability and to sustain the concurrent loss of data in two facilities,

For RRS:

while RRS is designed to provide 99.99% durability and to sustain the loss of data in a single facility.

Does this effectively mean S3 is replicated in at least 3 data centers while RRS is replicated in at least 2 data centers?

Answer 1

According to the same page that I assume you’re quoting:

Amazon S3’s standard and reduced redundancy options both store data in
multiple facilities and on multiple devices, but with RRS, data is
replicated fewer times, so the cost is less.

They imply that data is either replicated twice or more than twice depending on the service, with no further technical detail.

Slightly more detail here: Protecting Your Data