Why does diffraction work?

Question

I'd like an original and easy-to-understand answer, no ctrl+c,Ctrl+v.

Answer 1

easy to understand answer:

1+1=2,(-1)+(-1)=-2;constructive diffraction   (-1)+1=0;destructive diffraction

in constructive diffraction(cd) the waves with max amplitude in +ve dir combine to form a newer one, and the wave combination of max -ve amplitude also results in cd. in destructive diffraction a wave with +ve max combines with another one with -ve max to cancel each other. in single slit diffraction, when it takes place, one central max is obtained and then the energ falls. its graph is like the motion of a ball when dropped into a damp place. but in 2 slit diffraction the graph is uniform with dark & bright fringes repeating.