Understanding site access constraint

Hi, I found from the overview saying that “Workers can use sites indefinitely (backtrack, travel while another Worker is on-site extracting)”. On the other hand, I found statement on starter notebook saying that “one site can be accessed by 1 worker at a time”. For me, the statement in overview contradict the ones in starter notebook. Please correct my understanding.

thanks

My understanding is that “access” means “extract reward”.

thank you very much, it is clear now to me