Hi Jasraj,
You need to clarify your question a bit more.
In the beginning, we can see that sensor was defined:
sensor = rangeSensor;
sensor.Range = [0,10];
and then we called the function exampleHelperDiffDriveCtrl:
exampleHelperDiffDriveCtrl(diffDrive,controller,initPose,goal,refMap,map,refFigure,mapFigure,sensor)
If you look at the function itself, then you can see that the inputs are:
function exampleHelperDiffDriveControl(diffDrive,ppControl,initPose,goal,map1,map2,fig1,fig2,lidar)
so here, essentially rangeSensor/sensor was passed as lidar. And then if you follow along you'll see that:
[ranges, angles] = lidar(position, map1);
scan = lidarScan(ranges,angles);
If you want to learn more then look into what does lidarScan do with the outputs of lidar in the documentation here. Playing with the examples by changing parameters and reading the documentation should serve you well.
