Blog- is a discussion or informational site published on the World Wide Web and consisting of discrete entries typically displayed in reverse chronological order.
Sphere- a ball, globe, community or a collection.
Blogosphere-The totality of blogs, especially the unique jargons, cultures and shared interests created by their interconnection. The realm of Internet blogs and the people who read or write them.
The term implies that blogs exist together as a connected community (or as a collection of connected communities) or as a social networking service in which everyday authors can publish their opinions. Since the term has been coined, it has been referenced in a number of media and is also used to refer to the Internet.