In the realm of children's book design, a vector refers to a type of artwork created using paths defined by mathematical expressions. Unlike raster images, which are made of pixels and can lose quality when resized, vectors maintain their clarity at any scale, making them ideal for illustrations and graphics in children's books. This quality ensures that images remain sharp and visually appealing, whether viewed in print or on screens. Artists use software like Adobe Illustrator to create vector images, allowing for intricate designs and smooth edges that capture the imagination of young readers.