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ROS is capable of extending autopilot capabilities with a wider ecosystem of technologies that can run on more powerful computers.
MAVROSis a ROS package that can convert between ROS topics and MAVLink messages, allowing ArduPilot to communicate with ROS.
Some features of MAVROS:
can control/monitor drone states (set waypoints)
access telemetry and sensor data
provides tools for offboard control and data logging
Documentation for establishing a connection between ArduPilot SITL and ROS can be found here.
Example of ROS and ArduPilot working Togethertogether:
ROS can be used to capture data from cameras which can be processed by autonomy algorithms. The processed data (path planning) can be relayed with MAVLink commands back to ArduPilot through MAVROS. These commands to ArduPilot are control inputs that allow the drone to adjust its flight path based on real-time data.
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