Scalable Vector Graphics (SVG) is a file format used for creating two-dimensional vector images. Unlike raster images, which are made up of pixels, SVG images are composed of paths defined by mathematical expressions. This allows SVG graphics to be scaled to any size without losing quality, making them ideal for responsive web design and high-resolution displays. 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. SVG is widely supported by modern web browsers, making it a popular choice for web developers.