I have been asked this question so many times. When someone installs WordPress and goes into their editor window, down on the right hand side they find this.
So what does is exactly do? Well, I wish it was as simple as that. Your featured image can play several roles. And it can be dependent on your theme or even a plugin.
Let’s look at the Twenty Twelve theme. If we add a featured image and no images in the post itself, the image shows up above the post name.
But if we add a photo at the top of the post like this:
Now we get a post with two images. So for this theme if you wanted the image above the title, you would use the featured image. But if you want it below the title, you would insert it directly into the post.
Now let’s look at another theme. Here we are using the Genesis child theme Prose. The featured image works totally different here. If you have both a featured image and an image in your post, on y0ur blog page, it pulls the featured image in as the thumbnail.
And when you view the full post, you do not see the featured image, just the image inside the post. What this does it gives you the option to have a different image for your blog page thumbnail.
And if you do not add a featured image to the post, it will pull the image that is placed inside the post as the thumbnail.
Now if we look at a widget that comes with the Genesis framework, you will see that one of the settings is specifically for the featured image.
Where does this leave you? As you can guess, it all depends on your theme. So if you haven’t explored how the feature image integrates with your theme, maybe it’s time to. You just might be surprised.