A vlog or video blog is a blog (short for weblog) which uses video as the primary content; the video is linked to within a videoblog post and usually accompanied by supporting text, image, and additional meta data to provide context.
Diavlog, by the same token, is a video dialog. It follows a blog format in that it accompanies video clips with meta data relevant to the video. A diavlog could come out of a web cam recording, a video conferencing session, or even, a video by email sequence that grows with each response.
An MP3 blog is a type of weblog in which the creator makes music files, normally in the MP3 format, available for download. They are also known as musicblogs or audioblogs. MP3 blogs have become increasingly popular since the beginning of 2003. The music posted is normally hard-to-find, often has not been issued in many years, and selections are often restricted to a particular musical sub-genre or theme. Several MP3 blogs offer music in Advanced Audio Coding (AAC) or Ogg formats, as well as MP3.
One of the first widely known MP3blogs is Fluxblog, which was created in early 2003, and continues to offer a mix of music generally centered on recent rock and pop and offering commentary on the songs, artists, the music industry and music in general. There are now thousands of MP3 blogs covering a cornucopia of musical styles.
(Some definitions taken from Wikipedia, the free encyclopedia, New: Vidize.com focuses on video sharing and personal broadcasting)