ETL tools... what do they do exactly? In laymans terms please
etl
Solution
ETL stands for "Extract/Transform/Load". These tools take data from one source and move it into another. You can map schemas from the source to the destination in unique ways, transform and cleanse data before it moves into the destination, and load the destination in an efficient manner. You can schedule ETL jobs as batch processes.
Those data sources can be relational databases, spreadsheets, XML files, etc.
Who "uses" them? Depends on what you mean by "uses". They're just code and most of the time, they're scheduled as part of regular operations. There are no end-user features. They're totally for programmers to create and operations to operate.
Advantage over scripts? None. They are scripts written in a domain-specific language (DSL) focused entirely on "extract" from source, "transform" and "load" to destination. Most of the interesting part of the script is the field-by-field mappings at each stage.
Problem
I have recently been exposed to some ETL tools such as Talend and Apatar and I was wondering what exactly the purpose/main goal of these tools is in laymans terms. Who primarily uses them and if you use them, how they are (from my understanding) better than just writing some type of scripts.