AAC is a sound encoded file format developed by Fraunhofer IIS, AT&T, Dolby and Sony. Its name stands for Advanced Audio Coding. The AAC format is an industry standard and was created as an improved alternative to the most common MP3 audio file format. AAC files do have slightly improved features compared to MP3s. Let's say this format provides the opportunity for improved processing of frequencies above 16 kHz. At the same time, the sound quality of AAC files is closer to the original sound source.
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.