The steps to import new data into ServiceNow from a spreadsheet are: Load Data, Create Transform Map, Run Transform. Load Data is the process of uploading the spreadsheet file and creating an Import Set table that contains the data to be imported. Create Transform Map is the process of defining how the fields from the Import Set table map to the fields of the target table in ServiceNow. Run Transform is the process of executing the Transform Map and copying the data from the Import Set table to the target table.
Reference: Import sets, Transform maps

gs.print() and gs.log() are older and not available in scoped applications, whereas gs.debug(), gs.info(), gs.
warn(), gs.error() work in both scoped applications and global are therefore are more versatile going forward in future versions.
Reference: https://community.servicenow.com/community?id=community_question&sys_id=bd71cb29db98dbc01dcaf3231f9619c6