Many thanks for your replies!
The Blog would be independent from this forum, we will use a new domain name.
Blogs have been very popular on the Internet in the past a few year, many big sites now have a Blog section.
A Blog is usually written by one person, it's like a column on the newspaper, or a diary if you only intend to write for yourself.
Regular posting is very important, so it's much easier to build a hot blog if it's written by a group of members.
Everyone can post after registration, but very few blog visitors will write blogs, they add comments to the existing articles instead.
The blog posts will be categorized by topics (or authors), you can post anything you want.
As you can see, forum is a community, every visitor can start a topic. Blog is like an e-zine, the owners of the blog write the posts, or articles if they are not too short.
I hope you can get the basic idea with my very brief introduction.
Would like to see more feedback from other members.