SVG, or Scalable Vector Graphics, is a file format used for creating two-dimensional vector images. Unlike raster images, which are made up of pixels, SVG images are defined by mathematical equations, allowing them to be scaled to any size without losing quality. This makes SVG ideal for web graphics, logos, and icons. SVG files are written in XML, a markup language that describes the structure of the image. This means they can be easily edited with text editors and manipulated with CSS and JavaScript. As a result, SVG is widely used in modern web design for its flexibility and scalability.