Connection plugins allow Ansible to connect to the target hosts so it can execute tasks on them. Ansible ships with many connection plugins, but only one can be used per host at a time.
By default, Ansible ships with several connection plugins. The most commonly used are the :ref:`paramiko SSH<paramiko_ssh_connection>`, native ssh (just called :ref:`ssh<ssh_connection>`), and :ref:`local<local_connection>` connection types. All of these can be used in playbooks and with :command:`/usr/bin/ansible` to decide how you want to talk to remote machines. If necessary, you can :ref:`create custom connection plugins <developing_connection_plugins>`.
Because ssh is the default protocol used in system administration and the protocol most used in Ansible, ssh options are included in the command line tools. See :ref:`ansible-playbook` for more details.
You can set the connection plugin globally via :ref:`configuration<ansible_configuration_settings>`, at the command line (``-c``, ``--connection``), as a :ref:`keyword <playbook_keywords>` in your play, or by setting a :ref:`variable<behavioral_parameters>`, most often in your inventory.
For example, for Windows machines you might want to set the :ref:`winrm <winrm_connection>` plugin as an inventory variable.
Most connection plugins can operate with minimal configuration. By default they use the :ref:`inventory hostname<inventory_hostnames_lookup>` and defaults to find the target host.
Plugins are self-documenting. Each plugin should document its configuration options. The following are connection variables common to most connection plugins:
Each plugin might also have a specific version of a variable that overrides the general version. For example, ``ansible_ssh_host`` for the :ref:`ssh <ssh_connection>` plugin.
