get_field() gets the value of the field. the_field() outputs the content of the field. Both functions format the value the same way, basically the same way that WP formats the value of the main content editor. For a WYSIWYG field, if you want to get the value without formatting the you need go do get_field('my_field', false, false). The second argument is the post ID, set to false it means the current post. The 3rd argument tells ACF not to format the value.
