In PDI, transformations and jobs are made up of steps for performing various extract, transform and load operations. They are, in essence, the building blocks of the transformations and jobs. Steps are categorised based on their purpose; for example, there are input steps for reading in data, output steps for outputting data and transform steps for transforming and manipulating the data. See PDI Steps guide for a list of all of the available steps.

Hops are links between steps and describe the flow of the ETL process. You can create a hop between two steps by clicking the step you wish to start the hop from, press and holding shift, and draw a line to the corresponding step. By clicking the hop you can disable/enable it - disabled hops appear greyed out. Some hops are conditional and represent the flow of the ETL process under particular circumstances - for example when an error occurs. These hops are normally coloured, or have an icon over them to indicate their purpose.