What is the difference between data ingestion rules and social escalation rules?

Data ingestion rules help in fetching the data across the X platform for the keywords you specify whereas social escalation rules minimizes the number of conversations created by enforcing limits to the number of conversations. 

For example, if you want to track all data related to Apple by adding it to the data ingestion rules. You want to respond to posts mentioning both Apple and iPhone, then you can set up escalation rules to capture only those posts containing both keywords. This way, only posts with both terms are escalated into conversations.