Metafile is a generic term for a file format containing multiple types of data streams, along with descriptive metadata. A metafile may also be called a "container" or "wrapper" file. Archive files, library files, graphic files, and multimedia files are all common types of metafile.
The term "metafile" is most often applied to graphics file formats containing both vector and raster image data. These files contain a set of instructions that tell the graphics renderer how to draw a vector shape and text, and how to use an embedded bitmap image. Windows operating systems use the Enhanced Metafile (EMF) format as its standard graphics metafile format, while macOS uses PDF.
Other categories of metafile are often referred to using more specific terms instead. Archive files (like ZIP and RAR) compress any kind of data into a single file. Library files (like DLL) contain a combination of program code, data, and graphic resources. Multimedia container files (like AVI, MP4, and MKV) are a type of metafile that contain video, audio, and closed caption text data streams.