This document explains the basic ideas behind clusters in the PlanetScaleDB context.
In the context of PlanetScaleDB, a cluster is a set of resources that run one or more databases. Your application connects to a particular cluster, which provides access to all of the databases it contains.
Each cluster runs on one or more cloud providers and regions. The databases on a cluster can only deploy to the regions and providers for that cluster.
PlanetScale clusters correspond to Kubernetes clusters, which PlanetScale uses to run your databases.