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Is this what you are looking for?
Yes, that is correct. that one is the inlet.
The hot coolant flows from the engine to the heater core through the "inlet" hose. After circulating through the core, the coolant returns to the water pump through the "outlet" or "return" hose.
The pipe coming to the waterpump in front is the waterpump inlet and heater core oultet.
Hope this straightens out the confusion.