Network address translation is very common in private networks, for example the router in most homes performs NAT so that you can use the Internet.
does this mean for example a webserver, running behind a NAT could not be addressed
That's exactly right. In the same way that clients outside your home network can't access port 80 on your iPad (or whatever).
SSH bastions are a common set up and they work roughly the other way round to NAT boxes in that they sit in the public subnets and allow incoming traffic via SSH and then allow access to the rest of the VPC from themselves.
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Network address translation is very common in private networks, for example the router in most homes performs NAT so that you can use the Internet.
SSH bastions are a common set up and they work roughly the other way round to NAT boxes in that they sit in the public subnets and allow incoming traffic via SSH and then allow access to the rest of the VPC from themselves.