When building a data flow and analysing data a frequent requirement is to rename fields, for example, to make them more descriptive.
You can rename fields (and perform a wide range of other tasks) using the Transform node - see the online help for details:
Node help > Aggregation and Transformation > Transform
As an alternative, the attached 'Rename Fields' node is an easy to use Community custom node that allows you to rename specified fields by entering the input field name and the corresponding new name for that field. The field name can be entered manually or, if the previous node has been run, you can use the Input Fields functionality to insert the name from the property's context menu.