WMV is a common video file format developed by Microsoft and designed to store or transfer video data. It takes its name from the abbreviation of the name of the Windows Media Video technology itself, with which the file is encoded. Codecs for WMV format are installed automatically along with any version of the Windows operating system. Playing WMV files is possible on almost any media player. Such files may contain both Windows Media Video video data and Windows Media Audio audio data. The format also supports the use of DRM protections to prevent copying.
AMR is a sound file format with a specific focus. Created a long time ago, before the advent of MP3. some sources call the developer Ericsson. The name of the format is an abbreviation for Adaptive Multi Rate. Sound files of this format are intended for mobile devices and in GSM cellular networks. Using this format provides a small file size due to the technology of signal coding in the speech frequency range. Effectively compressing audio recordings of human speech makes this format often used in voice recorders on mobile phones, for voice recordings, and for MMS messages.