Introduction

Two pages on the same website can serve very different purposes. One may report what happened. Another may argue for a response. A third may be a paid promotion designed to resemble the surrounding articles.
Recognizing the kind of message helps you read it fairly. It tells you what the creator is trying to provide and which checks are most useful.
These categories are guides, not guarantees. A news report still needs reliable evidence. An opinion article can contain accurate research. An advertisement can make a true claim. The category helps you understand the message; the evidence helps you assess its factual statements.