People maintained blogs long before the term was coined, but
the trend gained momentum with the introduction of automated
published systems, most notably Blogger at blogger.com.
Thousands of people use services such as Blogger to simplify and
accelerate the publishing process.

Basically a blog contains these features:

title- which allows you to label your post
body- this is the content of your post
trackback- other sites can be linked back to your blog
permanent link- every article that you write has a URL
comments- this allow readers to post comments on your blog.

One of the advantages of blogging, is that it is made of only a few templates. Unlike, other websites that is made up of numerous individual pages. This make it easier for blog users to create new pages, because it already has a fix setting that include: slots for title, body of the post, category, etc.

Blogs can be described in many definitions and they are all
correct.

Blogs are instant publishing. You write, you cut-and-paste
images, you cut-and-paste links, you customize everything
through a WYSIWIG (what you see is what you get) interface, and
with one click you publish your information or article.

A frequent, chronological publication of personal thoughts and
Web links.

A blog is often a mixture of what is happening in a person's
life and what is happening on the Web, a kind of hybrid
diary/guide site, although there are as many unique types of
blogs as there are people.

Blogs are alternatively called web logs. However,"blog" seems
less likely to cause confusion, as "web log" can also mean a
server's log files.

A cross between an online journal and a bulletin board.

Business Blogs:

Can be used as a corporate tool for communicating with customers
or employees to share knowledge and expertise.

What does Blogging Provide to Small Business?

Blogging is a low-cost alternative to having a web presence.
For small business owners without the time to learn web html or
the money to hire a designer/developer, blogging offers an
inexpensive method to get your company's name out on the
Internet.

Updating the web log is a much quicker process than contacting
a web designer with changes or doing the coding and uploading
yourself.

Business blogs provide your small business with a chance to
share your expertise and knowledge with a larger audience. A
powerful benefit for consultants and knowledgeable workers.