API is systematic way for a website developer to query the listings within your account and get back real time information to be displayed on your website.
Data Feed is a nightly generate data file that contains all your on market properties. We have 2 data feeds available. One is in our own format, which can be imported into a separate database that feeds into your website. Another is in Zillow's format, as some users like to handle their own syndication to Zillow for better control.