SOAP API includes new, changed, and deprecated calls.

New, Changed, and Deprecated Calls

New Calls

The deleteByExample() call deletes big object data. Define an sObject that contains the fields in the big object’s index, with the values you want to target. The sObject acts like a template, and all rows that match the sObject’s fields and values are deleted.
Evaluates sObjects provided as an input for matches among Leads, using the matching rule specified in the input MatchOptions.

Changed Calls

describeSObjects() DescribeSObjectResult
The formFactor field in the ActionOverride subtype now supports the Small value, which represents the Salesforce mobile app on a phone or tablet.
search() SearchResult
The search() call returns a SearchResult object. The SearchResult object was updated to include a new searchPromoted parameter in SearchPromotedMetadata, which indicates that an article was promoted in search results. Admins define promoted search terms by adding to knowledge articles. Users who search for these keywords see the article first in search results. The related parameter searchPromotedMetadata was also added to EntitySearchMetadata.