Both Preview and Retrieve run a SOQL query to fetch source data, but they serve different roles:

• Retrieve (used in #Batch and #Data List ) defines which records are processed or displayed during execution.

• Preview (used in #Triggers and #Action Buttons ) does not affect input data; instead, it lets you inspect source records and their transformed values before execution.

In short, Retrieve controls the records that run, while Preview helps you validate data and transformations without changing the input.