https://docs.magento.com/m2/ce/user_guide/cms/widget-types.html

Widget Types

• Widgets

  TYPE	DESCRIPTION
  CMS Page Link	Displays a link to a specific CMS page. Allows you to specify custom text and title. When the link is complete, it can be used in content pages and blocks.
  CMS Static Block	Displays a block of content at a specific location on a page.
  Catalog Category Link	Displays either an inline or block-style link to a selected catalog category. When the link is complete, it can be used in content pages and blocks.
  Catalog New Products List	Displays a block of products which have been designated as new, for the duration of time specified in the product record.
  Catalog Product Link	Displays either an inline or block-style link to a selected catalog product. When the link is complete, it can be used in content pages and blocks.
  Catalog Products List	Displays a list of products from the catalog.
  Orders and Returns	Gives guests the ability to check the status of their orders and submit requests to return merchandise.  The widget appears only for guests and customers who are not logged in to their accounts.
  Recently Compared Products	Displays the block of recently compared products. You can specify the number of products included, and format them as a list or product grid.
  Recently Viewed Products	Displays the block of recently viewed products. You can specify the number of products included, and format them as a list or product grid.