Question about remapping

[shaochengluo]

Hello! I found in the tutorial you mentioned that:

If you have an odometry EKF node, also remember to remap the inputs to the AMCL node
<remap from="odom" to="odometry/filtered" />

I'm not quite sure about what it means, I have the similar layered EKFs for global localization and odometry, respectively. And they have their own published topic as odometry/filtered_map and odometry/filtered_odom. I'm not sure which to put to the remap command, and why I need to remap it in any way, the filtered odom is supposed to go to EKF instead of AMCL right?

Thanks a lot!