The company will provide an airline ticket. Most likely economy unless the flights are full then a business class seat to your departure city or a city that makes sense for you to sit reserve for a couple of days. For example you may have some reserve days prior to a trip starting. It would make sense to sit reserve at the scheduled departure city rather than going to another and commuting again. AMS and FRA are common cities to sit reserve due to the proximity of DUS, HHN and the wide reach of KLM and Lufthansa.
Yes the company covers hotel and ground transport as well.
Yes the company covers hotel and ground transport as well.