When using the Travel module of Rydoo, there are a couple of possible roles:
A traveler is a regular Rydoo user, that can have travel bookings and follow them up in his/her own account.
A traveler that can book trips for himself/herself.
The arranger is a person within the company that can book trips for travelers and guest travelers.
APPROVER (only with Advanced Travel)
The person responsible of the approvals before "confirmed" bookings are completed.
GUEST TRAVELER (only with Advanced Travel)
Is generally an external trip participant that does not have an account and can therefore not log into Rydoo.