A Blog (short for Web Log) typically consists of a series of entries containing content relating to a common topic, which are usually displayed in reverse order of date of publication.
An important part of a Blog is the ability for visitors to interact with the author(s) by posting comments and/or voting on the articles published.
Well written Blogs encourage interested parties to link to them, which in turn improves the Search Engine Performance of the website.
To find out how a Blog can benefit the performance of your website contact IASP.