The blogosphere is a term used to describe the millions of interconnected blogs on the Internet. The term was first used in late 1999 as a joke, and continued to be used sporadically as a humorous term for the next few years. In contemporary usage it may either be used somewhat facetiously, or may be used in an entirely genuine manner, depending on the user.
The word blogosphere is most likely a nod to the older, and more frequently used, logosphere. The logosphere has been used to describe a number of different things, but most recently was adopted as a term to describe the world of information that the modern communication age ushered in. Logosphere is derived from the Greek word for word, logos, and the word for world or universe, sphere. Blogosphere can therefore be understood as describing the universe of blogs, and also as evoking the concept of the logical, interconnected universe that the word logosphere describes.
The word blog, in turn, is a shortening of the term web log. Blogs have been around in one form or another for some time on the Internet, but the term was first used sometime in 1997. Blogs quickly gained popularity around the turn of the millennium, and their growth seems unlikely to slow down any time soon. Blogs are used for a wide variety of purposes: to record personal thoughts, to publish academic thoughts and written works, to discuss political topics, to post general news items, to post news items related to a specific area, to publicly discuss innovations and activities within a company, and essentially anything else one can conceive of.
Fundamentally, a blog is a solitary expression. A blog most often has only one author, who posts new items as they desire. Sometimes blogs will have multiple authors, but rarely more than a small handful. While readers can often interact with the author via comments, this level of interaction is still limited.
The blogosphere is a way of describing the social creature that grows from a critical mass of blogs. Because of the way blogs are constructed, and with the help of popular services like Bloglines or Technorati, blogs are ideally suited to interconnect with one another. Authors of a post may link within the post to another blog, they may comment on other blogs with links back to their own, or they may keep a blog roll of their favorite blogs. With such tight connections between blogs, information is able to be transmitted at an incredible pace. If one blog posts something that catches the attention of other bloggers, their reposting of that item, and the subsequent reposting of it by their readers means that the information can soon be all over the blogosphere.
This ability of the blogosphere to transmit items of information or concepts — commonly referred to as memes — is thought by many to be one of the most influential aspects of the blogosphere. News-transmitting blogs are able to uncover new stories and report on them from a number of different angles much more quickly than traditional media, simply by tapping the power of the blogosphere. People being oppressed or in some sort of dire strait who need their story told are often able to get it rapidly out to millions of people, simply by tapping the power of the blogosphere. Corporations are quickly realizing that the power of the blogosphere to transmit buzz about new products or services is unmatched by any traditional media.