Do we want largest or smallest priority in the A* algorithm?
It's just two ways of saying the same thing.  High priority means most urgent but is often represented by low numbers&nbsp;&ndash; my "number-one priority" is the most urgent thing on my to-do list.  Perhaps it would be clearer if people used phrases like "lowest priority value" or even "highest priority (lowest priority value)". It's often inconvenient to reformulate the algorithm to make high priority correspond to big numbers. For example, if I decide that "priority 10" means the most important thing on my to-do list, that kind of limits my lists to ten items, unless I want to number them 10, 9, ..., 1, 0, -1, -2, ..., which seems a bit silly.

Similar confusion comes up in other settings where smaller numbers represent bigger or higher things. For example, in photography, aperture is measured in f-stops but a higher f-number means a smaller aperture.