*lookup plugins* are a way to query external data sources, such as shell commands or even key value stores.
Before Ansible 2.5, lookups were mostly used indirectly in ``with_<lookup`` constructs for looping. Starting with Ansible version 2.5, lookups are used more explicitly as part of Jinja2 expressions fed into the ``loop`` keyword.
Before Ansible 2.5, lookups were mostly used indirectly in ``with_<lookup>`` constructs for looping. Starting with Ansible version 2.5, lookups are used more explicitly as part of Jinja2 expressions fed into the ``loop`` keyword.