What characteristic defines a blog?

A defining characteristic of a blog is that it is regularly updated with articles or posts. This consistent update is key to its nature, distinguishing blogs from static websites. A blog typically features new entries or content on a frequent basis, allowing for a dynamic flow of information that can engage readers over time. This regular updating encourages return visits and fosters ongoing discussions around the content.

In contrast, the other options describe features that are not typically aligned with the blog format. While a blog can touch on various topics, it is not limited to a single subject, and it can indeed include a range of interests. Additionally, blogs often foster user interaction through comments or shares, which enhances community engagement. Lastly, focusing primarily on sales does not characterize a blog; rather, it is more about sharing information, insights, or personal experiences.