Search the extracted values for a person or company name. This looks inside the declared fields, the raw extraction, the sender and the file name — the source documents themselves are not searched, and the term you type is never written to the audit trail.
Redact blanks the matching values, the raw extraction, the sender and the file name of that document; the amounts and the dates stay.
Kept: the source document itself, the file as it was uploaded or mailed in, because it is the evidence of the transaction.