API's (Application Programming Interfaces) is tool that allow your interceptor to communicate with pricefx and CRM.
This means you can use API's to retrieve data from pricefx or CRM and insert data into them. While these are the most common uses for API's, they can also be used for other purposes, although these may be less common.
https://pricefx.atlassian.net/wiki/spaces/INTERC/pages/5497094200/Interceptor+Method+API is common for all Interceptor Methods.
https://pricefx.atlassian.net/wiki/pages/resumedraft.action?draftId=5497389098&draftShareId=f435cbba-5709-4904-b37f-5b34710261b5 is used only for CLIC modules (Quotes, Rebates, Contracts, Compensation Plans).