Vlogging, short for "video blogging", is blogging through the medium of video. A blog is any web page updated on a regular basis with discrete entries, often delivered to a viewer who has subscribed to the blog and reads it using a third-party interface, or RSS aggregator, rather than visiting the website directly. An RSS aggregator allows the reader to consolidate multiple blog feeds into a single personalized web page.
A blog that primarily uses video to distribute its insight or message is called a vlog. Not many vlogs currently exist, but many trend watchers say that it's only a matter of time until the rich, personal medium of video begins to replace static text and images. The widespread adoption of broadband technology and the falling cost of bandwidth is another factor that will make widespread video distribution possible.
RSS enclosures allow a blogger to insert media into a blog post and have it distributed to the aggregators of those subscribed to the blog. Most frequently, this is used to distribute images alongside text, but it can also be used to distribute video alongside text and images. With the release of the video iPod in 2005, there is now a convenient and popular mobile medium for video, opening the door for the era of the vlog. A viewer watching a vlog stream might be compared to a television viewer, but the content creation is highly distributed rather than centralized, and the viewer would have access to thousands or even millions of channels rather than just a few dozen or hundred.
The first known videoblog entry was on November 27, 2000. Although the early 2000s were marked by attempts to create videoblogs, vlogging didn't truly emerge until 2004, when small communities of vloggers began to pop up and big media started to notice vlogging, with articles in the New York Times and other publications. Vlogging is still small today, but online video is starting to take off, with websites like Google Video and YouTube offering free storage space.
One of the key problems with vlogging is that there exists no unified standard for metadata, that is, tagging videos themselves with data that shows what they're about. Search engine technology is not sufficiently advanced that a search engine "spider" can watch a blog, tell what it's about, and index it accordingly. Before vlogging becomes mainstream, something along these lines may need to happen. Tagging is one possibility, but it requires special effort.