Answer:
The sketch is where the artist will determine the principal aspects of his/her final painting. So, there he/she will create poses, determine the point of view, the positions of the characters in the canvas. In a sketch the artist doesn't worry about the backgrounds of the scene or the complex aspects of the final composition. Instead, he/she will study how to compose the scene. Because of that, the sketch is rough, with edit marks, there's no care with the aesthetics, is just a preliminary step for the final composition. It's important because is where the artist will trace the painting and the way how the audience should look at it.
Explanation:
