A line in art is defined as a point moving in space, and it's one of the seven elements of art (line, color, shape, form, texture, value, space).
Color is the element of art that is produced when light, striking an object, is reflected back to the eye: that's the objective definition.
Shape is a flat area surrounded by edges or an outline. Artists use all kinds of shapes. Geometric shapes are precise and regular, like squares, rectangles, and triangles. They are often found in human-made things, like building and machines while biomorphic shapes are found in nature.
Space in a work of art refers to a feeling of depth or three dimensions. It can also refer to the artist's use of the area within the picture plane. The area around the primary objects in a work of art is known as negative space, while the space occupied by the primary objects is known as positive space.
Texture refers to the surface quality in a work of art. We associate textures with the way that things look or feel. Everything has some type of texture. We describe things as being rough, smooth, silky, shiny, fuzzy and so on.
