A set of agreed categories for where records belong, usually aligned to functions and activities. A good file plan improves findability and keeps retention and disposal consistent.
A file plan is the agreed map of where records belong, usually aligned to functions and activities. Following it improves findability and keeps retention and disposal consistent; creating ad hoc folders that others cannot find works against both.
IAR turns terms like this into working practice: assets classified against your disposal authority, stewarded by position, and ready to evidence.