S3 Texture Compression (S3TC), also known as DXTn or DXTC, is a group of lossy image compression algorithms originally developed by I3D and licensed to S3 Graphics for use in their Savage-series graphics chips. It has since become the industry standard for texture compression in 3D computer graphics, particularly within the DirectX and OpenGL APIs. The primary advantage of S3TC over other image formats like JPEG or PNG is that it is designed to be decompressed in real-time by the hardware on a Graphics Processing Unit (GPU). This allows for random access to texture data, meaning the GPU can fetch specific pixels without decompressing the entire file, which significantly reduces video memory bandwidth and storage requirements. The format consists of several variants, including DXT1 through DXT5, which offer different trade-offs between color depth and alpha channel transparency. While S3TC data is most commonly found wrapped inside DirectDraw Surface (DDS) containers, the S3TC designation specifically refers to the underlying compression technology that enables high-performance rendering in modern video games and professional visualization software.