Using the Mass Update script, we can build custom Mass Updates for users to perform. This functions just like a normal Mass Update, where the user selects the type of Mass Update, builds a search that returns the records to update, and then each search result is passed individually into the custom Mass Update script.
The script provides a single each
event handler that receives the internal ID and record type of the record that is to be updated.
Mass Update scripts must be triggered manually by users through the standard Mass Update interface.
Mass Update scripts have a massively high governance limit and are intended for commonly used, custom bulk processing.