https://docs.magento.com/m2/ce/user_guide/catalog/categories-custom-design.html

Design Settings

The Design section gives you control over the look and feel of a category and all assigned product pages, and page layout. You can customize a category page its assigned products for a promotion or to differentiate the category. For example, you might develop distinctive design for a brandA unique identity that defines a particular product or group of products. or special line of products, or apply an update for a specific period of time.


Design

The Scheduled Design Update section determines the range of dates when a custom design is applied to category pages.


Scheduled Design Update
  • Field Descriptions

    FIELD

    DESCRIPTION

    Use Parent Category Settings

    Allows the current category to inherit the design settings from the parent category. Options: Yes / No

    Theme

    Applies a custom theme to the category.

    Layout

    Applies a different layout to the category page. Options:

    No layout updates

    Preselected by default, and does not apply layout changes to the category page.

    Empty

    Use to define your own page layout.(Requires an understanding of XML.)

    1 column

    Applies a one-column layout to the category page.

    2 columns with left bar

    Applies a two-column layout with a left sidebar to the category page.

    2 columns with right bar

    Applies a two-column layout with a right sidebar to the category page.

    3 columns

    Applies a three-column layout to the category page.

    Layout Update XML

    Updates the theme layout with custom XML code.

    Apply Design to Products

    When selected, applies the custom settings to all products in the category.

    SCHEDULED DESIGN UPDATE

    Schedule Update From/To

    Determines the range of dates when a custom layout is applied to the category.