What is overlay in blogger

Overlay means having layers on top of the layers. That is, having one thing on top of another. When Blogger Post Image is clicked, that image opens above the post content and covers the entire screen. This is called Image Overlay.

If there is more than one image in Blogger Post, then the rest of the images appear as Thumbnail. And they can be seen one by one. If we want to go back to the post, then we have to close the Overlay with the Close X button on the right.