The Featured Image option in WordPress is an important feature that allows an image to appear next to a link, title and description when posts are listed on a page by category, tag or search term. It is recommended to set a featured image for all your posts as images make navigating posts easier and more enjoyable for the end user.
Featured images in WordPress can also display inside the post or page, and are often styled in the back-end to help create a consistent and appealing look.
Setting a featured image must be done while editing a post or page. To set the featured image, click on the Set Featured Image link in the Featured Image field on the right of the main text field. A new window will open allowing you to choose an image from your Media Library, an Image URL or Upload a New Image. Once you have chosen your method, click on Use as Featured Image next to the Insert Into Post button as pictured below.
1-The Feature Image field sits on the right of the main text field.