system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does water make some things slippery while also making other things more grippy?

When your hands are wet, it can make gripping things more challenging, like your feet on a pool deck or your tires on the road, right?. Climbers use chalk on their hands to get rid of moisture/better grip. So why does licking your fingers make it easier to count money or separate plastic bags (sticky)? 

I’m aware of the terms cohesion and adhesion in regards to water particles themselves but how does that apply to both the slippery aspect and sticky (for lack of a better word) of water against non-water things?
gpt
It depends on both the materials of the objects in contact and the amount of force being applied.  With the paper and grocery bag examples, there is little force and lots of adhesion.  Paper and plastic bags are very porous on a micro level, giving the water lots of surface to 'stick' with. Adhesion with water, though, is not strong enough to hold a climber.  The force of holding up a human body is too great. The water molecules instead slide around each other and the surfaces, reducing friction. This is not what you want when clinging to a cliff.