What is the meaning of Line_art?

Images that consist of distinct straight and curved lines placed against a (usually plain) background, without gradations in shade (darkness) or hue (color).

Artwork to be reproduced with one solid color, contrasted with artwork having tone or shading (halftones), or full color (color separations).

The outlines of a drawing as opposed to color, shading, and texture.

Source: wiktionary.org