Every post and page in WordPress can have a single featured image. Most themes use featured images for certain theme elements like post thumbnails or image slideshows.
Setting Featured Images
If your theme supports featured images, you can see a Featured Image metabox on the ‘Edit Post’ and ‘Edit Page‘ screens. If you do not see such metabox, make sure it is enabled in the screen options.
You can add your featured image by clicking on ‘Set featured image’.
Then upload a new image or select one from your media library in the appearing media popub box. Click on ‘Set featured image’ on the bottom right corner after you have selected your image.
As result you should see your configured featured image in the Featured Image metabox.
Do not forget to save your post or page by clicking ‘Update’ on the Publish metabox, otherwise your featured image is not saved.
Remove Featured Image
You can delete the featured image by clicking on ‘Remove featured image‘ on the Featured Image metabox on the ‘Edit Post’ and ‘Edit Page‘ screens (see screenshot above).