This block allows you to hide or show content (inner blocks which you add to this block) based on some criteria:
Post query visibility
Custom post types and custom taxonomy
You can select any taxonomy: categories, product categories, tags, and all custom taxonomies registered on your site.
You can select to show based on logined user or not, you can select also user role and choose definite User.
Custom field Query
This is interesting visibility condition based on custom field value. You can set visibility, for example, to show content only if post get value of meta field more than specific amount