Case 1 : When the corner and edge have different colors on top, you’ve hit the easiest F2L case. A clean 3-move setup is all it takes to pair and insert them effortlessly.
Case 2 : In this case, both the corner and edge have the same color facing up — like in the example where orange is on top for both pieces.
Case 3 : Here, the corner has its white side on top, which affects how you approach the F2L pair.
To solve more efficiently, you can pair a first-layer corner with its matching middle-layer edge and insert them together, instead of doing it in two separate steps. This technique is known as F2L, short for "First Two Layers."