There are several main types of graphics file formats. Bitmap formats store exact pixel data that maps to an output device's display surface. Vector formats contain mathematical descriptions of lines and shapes rather than pixel values. Metafile formats can contain both bitmap and vector data, and provide languages to define graphic elements that can be transferred between platforms. Scene formats contain instructions for rendering programs to construct images from portions defined in vector files. Multimedia formats allow different data types like graphics, audio and video to be stored together.