> For the complete documentation index, see [llms.txt](https://portainer.gitbook.io/portainer/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://portainer.gitbook.io/portainer/the-portainer-agent/why-use-the-portainer-agent.md).

# Why use the Portainer Agent?

## Purpose of the Portainer Agent

Docker Swarm introduces the concept of clustering nodes into a 'Swarm' and brings services, tasks, configs and secrets as cluster-aware resources. Cluster-aware means that you can ask for a list of services or look at a task inside any node on the cluster, as long as you’re operating from a 'manager' node.

Thus we have found a limitation of Docker: containers, networks, volumes and images are **node specific** resources, **not cluster-aware**. So when you want to list all of containers, networks etc inside your cluster, you are not able to, you can only ask a specific node for a list of its resources. When running the Agent however, you can treat containers, networks, volumes and images as cluster-aware resources. 

**This means you can now use Portainer to access all of the containers, volumes, networks etc in your entire cluster.**