We know that there's a difference between propositional logic and first order logic or predicate logic. Propositional logic concerns itself with propositions, which are statements or sentences that follows the principle of bivalence. On the other hand predicate logic is concerned about predicates, which are like an immature proposition (Immature because of the unknown value of some variable $x$ for any propositional function $p(x)$). If we can differentiate between compound propositions and propositions, then it's also possible to identify a proposition involved in propositional logic by its atomicity.
Now if we abstract away everything about these propositions or predicates, and think of them as objects (As objects don't have any constant definition. It depends on any specific context.), how can we now make a distinction between objects of propositional logic and objects of predicate logic? Is there any specific terms for them?
For example, because the first object doesn't depend on anything, it could be called "independent" object, whereas the other could be "dependent" object or "x-dependent" object.
Also, I might've made one or many mistakes in this post, technically or terminologically, if so, please let me know.