Lets talk about texture
Pick up your hand and rub your fingers together. Do you feel that? That's called texture.
Texture is also one of the seven elements of art. Texture can be felt or implied.
An example of felt texture is the sensation you experienced when you rubbed your fingers together. You usually find this kind of texture in 3d artworks.  The other kind of texture is implied.
Implied texture is found in 2d artworks. Artists create the illusion of texture in an artwork by combining visual elements like shapes, lines, colours & values. Artists can simulate a real texture like the Hyperrealists or invent their own texture like Vincent Van Gogh in his painting Starry Night.

Elements of Art: Texture | KQED Arts Video by KQED Art School