There are two contracts in this package: Installment Payment Plan and The Settlement Agreement (aka Cash-for-Keys).
This Installment Payment Plan is for when a tenant agrees to pay you back for an outstanding amount. This may be for any number of reasons, such as reimbursing for property damage or outstanding rent. This is a type of settlement between you and the tenant which can be used in a court of law.
This Settlement Agreement (sometimes known as Cash-for-keys) is when the Manager agrees to pay a troublesome tenant to move out. Some Managers will never use this Agreement, but if you have a tenant that you are worried about damaging the property further and you just want them to leave, this Agreement is drafted to encourage them to leave.