XML : .idea Folder in Android Studio

I found out Folder .idea in a sample project. In that File Modules.xml is there, content of the same is as below,

  <?xml version="1.0" encoding="UTF-8"?>  <project version="4">   <component name="ProjectModuleManager">    <modules>       <module fileurl="file://$PROJECT_DIR$/.idea/android.iml" filepath="$PROJECT_DIR$/.idea/android.iml" />    </modules>   </component>  </project>    

If I paste Directory Location in place of PROJECT_DIR it will look like below

  <module fileurl="file://C:\Users\DRONE\Documents\android/.idea/android.iml" filepath="C:\Users\DRONE\Documents\android/.idea/android.iml" />    

Question is,

1. Is it fine to just alter Backward Slash to Forward?
2. Do I need to edit this file or let it be the way it is?
3. What is the function of android.iml?