A vector graphic is a digital image comprised of points, paths, curves, and geometric shapes. Unlike raster graphics, which use a fixed grid of pixels, vector graphic files have no fixed resolution and can be resized, stretched, and otherwise manipulated without any quality loss. Graphic designers and illustrators use vector graphics for simple drawings, logos, icons, and illustrations. The individual characters in a font file are also vector graphics.
Paths in a vector graphic consist of points linked together. A point along a path can represent a sharp corner or a smooth curve (known as a bézier curve). When a path forms a closed loop by linking the end back to the beginning, it becomes a solid shape. You can adjust a path's stroke to change its width, style, and color; you can also fill an enclosed shape with a color or gradient.
A vector graphic's file size is typically much smaller than that of a raster graphic. A vector graphic file saves the mathematical information that defines the paths and shapes, along with their stroke and fill properties. Since this information is all stored as numerical values instead of individual pixels, a complicated vector graphic will have a smaller file size than a similarly-detailed raster graphic.
NOTE: Common vector graphic file types include Adobe Illustrator (.AI), Encapsulated PostScript (.EPS), and Scalable Vector Graphic (.SVG).