It is possible to have different URLs (see below) to invoke the same webroutine as a webpage.
Let's look at the definition for an example webroutine, MaintainRecord:
Based on the WEBROUTINE definition, this webroutine can use the optional ServiceName property on the WEBROUTINE definition to invoke the WAM:
The ServiceName does not require further qualification, as it must be unique across the partition.
The second URL option uses the combination of WAM name and the webroutine name as a unique combination.