Analysing an organisation's business activities to decide what information and records need to exist, how valuable they are, and how long they must be kept. Appraisal underpins retention and disposal authorities.
Appraisal is the analysis that sits beneath every retention rule. By examining what the business actually does, and the risks and obligations attached, it identifies which records must exist and for how long, which a disposal authority then formalises. Staff input often matters, because they know what is really used to run services.
Appraisal is the analysis; the disposal authority is the documented outcome. Appraisal decides what records matter and for how long, and the disposal authority records those decisions as authorised retention and disposal rules.
IAR turns terms like this into working practice: assets classified against your disposal authority, stewarded by position, and ready to evidence.