What tool is used to import data from various data sources, and map that data into ServiceNow tables?

A Transform Set (or Transform Map) is a component *within* the Import Set process that defines the mapping rules, but it is not the overarching tool for importing data.

"Data Pack" is not a recognized or standard ServiceNow tool used for data import and mapping.

Update Sets are used to migrate configuration and development changes between ServiceNow instances, not to import bulk data from external sources.

Import Sets provide the comprehensive framework in ServiceNow for staging data from various sources and then transforming it into the desired target tables within the instance.