Heat Pump Defrost Question

https://blogfreely.net/galimelfxx/comfort-experts-on-refrigerant-leaks-and-ac-repair-for-north-fort-worth-systems

Heat Pump Defrost Question Is it normal for a heat pump to blow steam from the outdoor unit in winter? Ours did that during the freeze last February and I panicked a bit. Sounds like it might just be the defrost cycle from what I'm reading here