delete category name in the pages

What theme are you running?

Are you referring to Pages or Posts because they are two different types or rather, what we call Post Types.

  • Pages are normally controlled via your page.php template file
  • Posts are normally controlled via your single.php template file

Commonly you will find category and tag functions in your single.php file, but calls to such functions are not strictly limited to a single.php file. They can in fact be used in multiple theme files.

So for example,

  • if you are viewing a Single Post, then look within single.php
  • if you are viewing a list of your Posts, then look within archive.php

You will be looking for template tags such as,

<?php the_category(); ?>

  or...

<?php the_tags(); ?>