WordPress is great in many ways and comes with a lot of built-in features.
Some administrators (me included) choose to remove some standard functions to improve speed and/or security.

I usually remove the following features by default.

remove_action('wp_head','wp_generator');
remove_action('wp_head','wlwmanifest_link');
remove_action('wp_head','rsd_link');
remove_action('wp_head', 'start_post_rel_link', 10, 0 );
remove_action('wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0);
remove_action('wp_head', 'rel_canonical');