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When we talk about level of review, what we are essentially asking is, "How many other people looked over this information before it got put out into the world?" And if the answer is more than zero, there's another question: "Who are those people?"
Some types of information, like posts on social media, go through virtually no review at all before they are published. Others, like research articles in scholarly journals, go through a large amount of review before they are published (i.e., peer review). Others still can be anywhere between those two extremes. It may help to think of the different review levels on a sliding scale, with publications getting no prior review on the left side and publications getting a lot of review on the right. Let's take some publications by Neil deGrasse Tyson as an example.
An X post by Dr. Tyson would fall on the far left side of the scale. These posts are published immediately and are not subject to review by anyone except the poster. A book on astronomy for non-experts would fall closer to the middle, but still leaning toward the left side. The book was reviewed by at least an editor, but probably not by any other astronomy experts. It underwent more review than a tweet, but definitely less than a peer-reviewed journal article, which would fall all the way to the right. Peer-reviewed publications typically go through review by an editor and at least two experts prior to publication.