We're glad you asked.
TwineSocial defines a Feed as a stream of content coming in from a social media network. It is possible (and even common) to have multiple Feeds bringing in separate content from a single social media network. The screenshot below shows a total of three (3) Data Feeds.
In short, Data Feeds are content streams, and counted independent of the networks they may be crawling.
Note: As with all Plan limits and features, Data Feed quantities apply across an entire TwineSocial Account and all Campaigns.