Why are the sides of the beam stretched when texturing?

Question

3D

Good evening!
Such a question: I take a cube, stretch it - I make it like a beam, after that I start applying a texture to each side of the beam, the texture fits normally on its upper and lower parts, but for some reason the texture stretches on the side ones .. What could be the problem? Thank you in advance for your help!

Answer 1

Look towards UV mapping.