What is the Difference between Data Transformation vs Transportation?
Transportation is just moving data from one place to another - in ETL, from source system to either staging area, data warehouse or data mart. 

Transformation is changing data structure so that it meets data warehouse needs - i.e. star schema, denormalization, aggregation, calculations, data cleansing, data enrichment etc. 

Both happen while ETL, but the "T" from "ETL" stands for Transformation.