> A microservice is deployed independently, has its own hardware and can scale independently from the rest of the system.

Nicely articulated

> If there are multiple services and they all share hardware, they're not really microservices.

You just described most microservice deployments on Kubernetes ;)

In this case, they run in containers, so they can actually scale independently. For this purpose, it's as if they were running on independent hardware.

Even if we had separate cloud servers - such as EC2 on AWS - for each service, technically they are not really independent hardware.

But for the purposes of deploying, hardware capacity allocation and scaling, you can see them as such. The same goes for containers orchestrated by K8s.

Don't we have a term for that — software coupling?

A microservice architecture has weak coupling.

it's coupling via network calls instead of in-memory calls