ASF file is primarily associated with Advanced Streaming Format by Microsoft Corporation. It often contains Windows Media Audio (.WMA) or Window Media Video (.WMV) data.
An ASF file consists of three parts: header object with information about the file itself; data object of the media stream, and index object which can support random access to data.
ASF file is unique for its small size which makes it easy to transmit through Internet. Data of figures, sounds, and motion pictures can all be contained in an ASF file.