If you've started messing with Red Hat Ansible Automation Platform 2 or the upstream Ansible 4 release (ansible-core 2.11 + community-supported collections), you've probably noticed that a number of the formerly "batteries included" modules have been moved out into Ansible Content Collections by upstream.
There's a useful kbase article that talks about which modules moved to which content collections at https://access.redhat.com/solutions/5295121.
In most cases, your playbook doesn't have to refer to an old module that's moved to a content collection by its "fully qualified collection name" (FQCN), but can keep using its short name. The catch is that the content collection does need to be available to your execution environment (whether that execution environment is a container-based EE that you're using with ansible-navigator or you're running playbooks directly on the control node in the old way with ansible-playbook).
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