WordPress allows adding captions to the images you upload. These captions are displayed under their respective images in a small font. Although captioning can help better describe images you use in your blog posts, you might want to disable them completely.
Copy and paste this code to your theme’s functions.php file to completely disable image captioning in WordPress:
add_filter('disable_captions', create_function( '$a', 'return true;' ));
The above function will completely disable captions for your WordPress website.