This chapter introduces the fundamental ideas behind Extract, Transform, Load (ETL). Before building pipelines, it's necessary to understand what ETL is and why it's used in data processing. We will look at how ETL fits into the broader picture of data integration.

You will learn to:

• Define data integration and the specific role of ETL.
• Break down the ETL acronym: Extract, Transform, and Load.
• Understand the primary reasons organizations use ETL processes.
• Recognize the basic difference between ETL and the related ELT pattern.
• Identify common types of data sources and target systems involved in ETL.
• Outline how to determine the basic needs for an ETL task.

By the end of this chapter, you will have a clear definition of ETL and its place in managing and preparing data.