When a set of parallel lines is intersected by a transversal line we get sets of corresponding angles. These are angles which lie on the same side of the transversal and both of them are either above or below the parallel lines.
In total there are 4 sets of corresponding angles formed when a transversal intersects a set of parallel lines.
Transversal lines can intersect sets of lines which are not parallel also and form similar corresponding angles. The only difference in the case of parallel lines is that the angles in each set of corresponding angles are equal.
Corresponding angles are sets of angles created when the transversal intersects the parallel lines. They lie on the same side of the transversal and both of them are either above of below the parallel lines.
I often find it easier to understand mathematical concepts when I can see it in front of me, so here is an image that might help.
Notice that the corresponding angles occupy the same positions as one another. For example, angles A and E are both above one of the parallel lines and both on the left side of the transversal. In a pair of corresponding angles, the measures will always be congruent (equal in measure).