Blogging
Initially, blogging involved a personal web log, in which a person would journal about their day. From "web log" came the term "blog."
Like most new innovations on the Internet, many entrepreneurs saw a marketing potential in having a blog, and blogging took off from there. Not only can a blog be used for marketing, but also, a blog can be a home business in and of itself.
Podcast
A podcast is an episodic series of digital audio or video files which a user can download and listen to. It is often available for subscription, so that new episodes are automatically downloaded via web syndication to the user's own local computer, mobile application, or portable media player.
Vodcast
step beyond podcasting, vodcasting, also called video podcasting or vlogging, adds video to the downloadable sound files podcast listeners are used to. Download the video files is a simple matter of subscribing to a vodcast in one of the many freely available directory programs.