Objective vs Subjective

This comes down to control.  Usually, in climbing, these two words are associated with Danger.  Objective dangers are the dangers you really have no control over (lightning, falling rocks, bees nests), and subjective dangers (I’m going to leave my rain jacket,only bring half the rack, or climb with an inexperienced climber).

They can relate too. “I’m going to go climb that loose cliff in the approaching thunderstorm.” Objective dangers can and should be minimized, but can’t be written off.  Wearing a helmet mitigates again falling rocks, but does nothing to prevent falling rocks.  Climbing a loose chossy climb invites falling rocks.

There are other things that are objective and subjective in nature at least with respect to your control over them.  Ape index, for example.  

You have some control over some things, but you have almost no control over most things.

‍