Variable fonts are a type of font technology that allows a single font file to contain multiple styles and weights. Instead of needing separate files for bold, italic, or light versions, a variable font can adjust its appearance dynamically. This means designers can create a wide range of typographic styles while using less storage space. These fonts use a single, flexible file format that can be manipulated through specific parameters, such as weight, width, and slant. This flexibility not only streamlines web design but also enhances performance, as fewer font files need to be loaded, improving page load times.