A blog was initially called a weblog. The concept of a weblog was more on a personal level where users would share their most honest day to day experiences online. It further evolved into sharing of knowledge in a particular domain for others to read and gave like-minded people a platform to interact and share their ideas. This is now what we call as blogging. The major points that differentiate a blog from a website are: 1. A blog is regularly updated. There is no point of keeping a blog that is not updated with new posts on a regular basis. 2. A blog most of the time offer a discussion panel where people can come and leave their comments or take part in a discussion.
People often confuse a blog with a website. But, to understand more clearly a blog is a website but a site is not a blog.
Marketers saw the potential of blogging for fulfilling their marketing goals and from then and there blogging got a new dimension.