Featured image or previously known as post thumbnails is the very important & popular feature of the WordPress. Today 90% of the themes on marketplaces like themeforest, creative market and others make use of this feature.
In general a Featured Image is the image which is assigned to your blog’s post and it’s used by theme for many functions like related posts, recent posts widget, featured posts sliders, post page and homepage etc.
How To Add Featured Image:
It’s quite simple to add the featured image to your blog’s posts. Navigate to WP Dashboard > Posts > Add New > Bottom-right of the post edit screen. Here you’ll see a box named “Featured Image“, add your image there and hit the publish/updated button of the post editor.