Facebook is easily the biggest social media website available these days. Some people eschew the place as a complete waste of time and energy, which, it can be if you're not smart about how you use it.
One of the first questions a lot of authors have when getting on Facebook is what kind of page to make. Some people prefer making pages for their specific books, while others make pages identifying themselves as writers or authors. To be honest, there are pros and cons to both approaches, which I'm going to go over here.
Having a page for a specific book gives the page a specific focus. If your book is about demonic possession, you don't get distracted and post things about aliens, bigfoot, or serial killers. You post things about demons, possessions, hauntings, ghosts and the like. You post excerpts and reviews and sales for that specific book, or if you have other books in the same vein, or even in a series, you post those.
If you have multiple books, you have multiple pages, which means more ways for people to come across your work.
If people are looking for your book, they can search up your book. Many people remember book titles before they remember authors, and so when they tell their friends about this great book they're reading, they tell them the title, usually. So having a page for your book means it will come up quicker when people go to look for it. You don't have to worry that a search will bring up your name, which might be skipped over as they look for the specific word or phrase that is your book's title.
There are cons to a book page though as well.
A specific focus means other subjects would be out of place. This means a short list of subjects available for content without deviating from the subjects your book is about.
A book also gains age over time. After a while, it becomes harder and harder to find fresh content to post on a regular basis. Wait long enough and all you'll really have to share are bits of new reviews, if you're that lucky.
There are cons to an author/writer page.
Having only a single page for all your stuff means less ways to find you than if you had multiple pages. As well, you're relying on people enjoying your writing enough to make sure they note your name, as well as the book. As I said above, people will usually remember the book before they remember the author, and it takes two or three good works before people start looking for you specifically.
Now. Looking at the lists above, it certainly seems like there are more pros to a book page than an author one. It's important to remember though that the pros and cons are not equal. It doesn't matter if you have multiple pages that can lead people to you if those pages are updated infrequently, or are even inactive. Whether author or book pages, they need to be active, the more the better. A good page should have a post at LEAST once a day, if not two or three. After all, if your pages slip due to inactivity, it's more likely your post won't be added to people's feeds. In the meantime, the more posts you make, the more likely you'll get Likes, Comments, and Shares, which is how people get led back to your page.
You should also take into account your time constraints. It takes time to find content and post it, even if you take advantage of the ability to schedule posts ahead of time. If you're scheduling two or three posts a day, expect to spend more than a few hours searching up and aligning stuff, and that's just for one page. It can really turn into a full-time job just keeping your social media up and running, and that's a lot of time which can be better spent writing your next book, or short story.
So I personally think an Author/Writer page is the better choice, just in terms of time needed to keep it active, and flexibility in posts. After all, it's going to be pretty tedious if you have to create a new page every time you release a new book.
But that is just my opinion. Feel free to look at my page and decide for yourself!