A “transformation” in Informtica repository is the definition for a process that generate, modify, or pass data.
A process has inputs and outputs. In Informatica repository, the inputs and outputs of a transformation is called “Port”. Each port is like a column of a table. A port may have the datatype, precision and scale to describe the data. You can specify a port as Input, Output, or Variable.
Rows of the data is passed to a transformation via the Input ports and individual rows will be passed out as output ports from a transformation.
A transformation’s outputs may be the inputs of another transformation. The set of transformations forms a mapping or a mapplet.