wpadminbar (WordPress Header Bar on Top)

Just to clarify, the admin bar only shows up if you’re logged in. Visitors to your site who don’t have a user account will not see the admin bar. That being the case, I personally never go through the trouble of removing it (I also find it quite helpful).

If you still want to remove it, probably the easiest solution is to add the following line to functions.php:

show_admin_bar(false);