When the incoming and the reflected waves meet each other, as a result of their interference a waveform is created along the rope.

Clicking on the „∑” sign, observe the standing wave formed by their interference!

At the fixed reflecting end and at half wavelength distances from here in the “C” points there are nodes, and between them exactly in the middle, in the “D” points, there are antinodes.
The reason is that in the “C” points the two waves are always in opposite phases and so they extinguish each other. In the “D” points their phases are always the same, and here they intensify each other.