In addition to line, shape, value, and color, another visual element that
can be important in art is texture. Texture is anything in art that engages
our sense of touch. Some artists make extensive use of texture. Some hardly
use it at all.
There are two types of texture: actual and simulated (fake):
With actual texture, there is something there in the materials that we could experience if we touched the artwork.
With simulated texture, the artist is creating an illusion of texture that isn't really there. The term for this is "trompe l'oleil" (french for "fool the eye")
Leon Kossoff, British, mid-late 20th century:
This painting demonstrates actual texture. Your eye tells you that the paint has a thick/rough texture, and this is in fact true.
James Rosenquist, American, mid-20th century:
This painting demonstrates simulated texture. Your eye tells you that it detects a texture of cellophane stretched over a doll head. But in fact if you touched this painting you would feel a fairly flat surface of paint on canvas.