The Featured image is known as post thumbnail. It is generally a themes feature. It has many advantages. Your website looks like beautiful if you add featured image in your website. Adding a featured image is very easy through WordPress. You can add featured image while creating posts or pages.
How to insert featured image WordPress
Step-1: Login to WordPress.
Step-3: Now click the Set Featured Image option to add featured image into your post or page.
Step-4: Click Upload button to upload new featured image or select an existing one.
Step-5: Select a file and upload.
Done! If you have any query about this please submit a support ticket.