AlwaysOn: Why there are two options to enable a secondary replica for read workload?

Please refer to

https://blogs.msdn.com/b/sqlserverstorageengine/archive/2011/12/22/alwayson-why-there-are-two-options-to-enable-a-secondary-replica-for-read-workload.aspx

 

Thanks

Sunil Agarwal