When people say they only wash their hair once a week, what do they mean?

Do they mean they only shampoo it once a week? Or do they mean they don't wet it in the shower at all but once a week? I'm sure this differs for everybody but I'd like some answers on this lol from both curlies, straight haired people, wavy, and everything in between, what are you talking about? Lol. Explain in detail how often you shampoo your hair, how often you wet, wash, or condition your hair, what is everybody's actual WEEKLY hair routines because I am confused lol