Answer:
So we can maintain high quality designs at any graphic scale.
Step-by-step explanation:
Unlike other graphic formats which simply define colors for fixed pixels, vector graphics define points and shapes (vectors) which are then used to draw the graphic at the desired and appropriate resolution.
Our graphic can look good at any resolution, no matter how large it gets. If we take a png or jpg file and make it extremely large, you'll notice the image begins to get blurry, because the pixels are being stretched and colors are being predicted or matched for the larger scale.