What makes some questions a 'practice problem' and others a 'conceptual question'?
A "practice problem", as I've found, is usually an exercise that tests students on their ability to directly apply essential concepts. They usually always involve some kind of computations that lead to a numeric answer. In the sphere of calculus, for example, a practice question would be:
Evaluate the derivatives of the following:
#3x + 9 = tan(y)# #ln(sin(4x)) = 3x# #e^(6x) + 3y = 0#
Each of those problems requires students to apply a certain principle (ex. implicit differentiation, chain rule) to solve them, and they all have some numeric answer.
A "conceptual problem" typically tests understanding of key ideas. Consider this physics problem:
You're pushing a crate along a flat, rough surface. Which of the below is not an 3rd Law Pair?
- Normal force between your hands and the crate
- Normal force between the ground and your feet
- The weight of the block on the ground, and the normal force the normal force of the ground on the block.
You need to have some understanding of what a Newton's 3rd Law Pair is to get the right answer (3) here.
In my experience, conceptual questions are typically more challenging, since they require a much better understanding of the concepts than practice questions do (better question-writers than me will write much more challenging problems). Also, the higher up you go in your education, the more conceptual and less computational stuff gets.
Hope that helped :)