The strategy feature allows you to add control on how a play is executed by the hosts. Currently, the default behavior is described as being the linear strategy, where all hosts will execute each task before any host moves on to the next task. As of today, the two other strategy types that exist are free and debug. Since Strategies are implemented as a new type of plugin to Ansible, more can be easily added by contributing code. Additional details on Strategies can be found at http://docs.ansible.com/ansible/playbooks_strategies.html.
A simple example of implementing a strategy within a playbook is as follows:
--- # Sample simple playbooks structure/syntax - name: Install MySQL Playbook hosts: dbservers strategy: free tasks: ...