WordPress was originally used as blogging software (and still is) though it has since become popular for web sites also. You do not need to include a blog on your web site in order to use WordPress. We have created a number of sites that do not have any blog at all but the client wanted the ability to update content themselves so we used WordPress.

We do suggest having a blog because it will help with your search engine optimization. Though we only suggest that if you plan on updating the blog on a regular basis, otherwise having a blog without any updates is not going to do you any good.