MY ONE BLOGby Manishdai
Data & Analytics

What is ETL?

Quick answer

Extract, Transform, Load: a process that pulls data from sources, cleans and reshapes it, and loads it into a destination such as a data warehouse.

ETL, explained

ETL pipelines are the plumbing of analytics. In the extract step, data is collected from databases, APIs, spreadsheets, or logs. In the transform step, it is cleaned, deduplicated, joined, and converted into consistent formats, such as standardizing dates or currencies. In the load step, it is written into a data warehouse or data lake.

A common modern variation is ELT, where raw data is loaded first and then transformed inside a powerful cloud warehouse. For example, an online store might run a nightly pipeline that combines orders from its shop platform with ad spend from marketing tools to calculate cost per acquisition. Reliable ETL needs monitoring, testing, and clear data ownership.

Related terms

Data Cleansing

Finding and correcting errors, duplicates, and inconsistencies in data so it is accurate and usable for analysis.

Data Lake

A central repository that stores large volumes of raw data in its original format until it is needed for analysis.

Data Pipeline

An automated series of steps that moves data from one or more sources, transforms it, and delivers it to a destination for use.

Data Warehouse

A system that stores cleaned, structured data from many sources, optimized for reporting and business analysis.

Orchestration

Automated coordination and management of multiple systems, services, or tasks so they work together as a complete workflow.

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