A blog is basically a website, only the format of the content is usually more personal, and it's not uncommon for a blog to have only one author who is also the blog's operator.
Whether a blog is better than a regular website depends on a few factors:
- Goal: What do you want to achieve with the website? Do you want to inform visitors about your company or products, or do you want to demonstrate your expertise?
- Resources: Can you bring up the necessary resources to create content on a topic over months and years, or do you want to sit down once, create content, and then focus on the core business?
- Product: What is the product of the business: expertise or something tangible?
A blog is all about content creation. The product of a blog is its content. A blog that does not publish content on a regular basis loses relevance and reach every day.
A regular website is not about content; it's purely informal. You present your products or your company to potential customers. This content is created and updated at irregular intervals.
If you want to build reach on the Internet, you need a blog because you can only achieve reach through content. For all other purposes, you can resort to a website, and you won't go far wrong.
Ideally, you combine a regular website with a blog. On the website, there is information about the company and the products – on the blog, there is content that attracts prospects and turns them into customers.