The Ansible control node is the central machine that manages automation tasks and executes playbooks across multiple remote hosts. It is essential in Ansible automation because it serves as the command center, where configurations, scripts, and inventory files are stored and executed. The control node communicates with managed nodes over SSH, using agentless automation to enforce configurations, deploy applications, and streamline IT operations. By eliminating the need for manual intervention, the control node enhances efficiency, scalability, and consistency in infrastructure management, making it a powerful tool for DevOps and system administrators.