SOAP API includes changed headers and changes to some data types.
Connect REST API
Integrate mobile apps, intranet sites, and third-party web applications with Salesforce using Connect REST API. Copy products from a cart to a wishlist and work with current carts. Get externally managed accounts. Get the body of a quick text. Send survey invitations by email.
Einstein Analytics REST API
Create, update, and retrieve auto-install requests for embedded apps using the Einstein Analytics REST API. Query replicated datasets by category and create new Salesforce datasets. Get detailed node data for individual dataflow jobs.
User Interface API
Work with related lists, use lightweight resources to get default values to create and clone records, and enjoy using more objects with User Interface API.