Kettle is a tool belonging to Pentaho suite, in fact, it is also called PDI or Pentaho’s Data Integration.
Kettle is a tool that is called ETL (Extract- Transform-Load). That is, a tool for Extracting data from a source, Transforming such data and Loading the data elsewhere.
These tasks are typical of the migration process, integration with third parties, exploitation of Big Data,… and in general, one could say that they are necessary in almost any medium or big project. Therefore, Kettle was created with the intention of facilitating this task, so we don’t have to go into detail about the implementation of how to do each of these tasks, but simply specify what we want to do. For that reason, in many places these types of tools are qualified as metadata tools, because they work at the definition level saying what to do, but not detailing how it is done, this is hidden from our eyes, which is very interesting in most cases.