What is the Difference Between a Live Connection and an Extract?

Tableau Data Extracts are aggregation-optimized snapshots of data that are stored in system memory and maybe rapidly retrieved for display.
For instance, hospitals that monitor incoming patient data must make choices in real-time.
Tableau may receive real-time updates thanks to live connections, which reflect any changes in the data source. For example, hospitals must track a patient’s weekly or monthly trends, which necessitates data extraction.