When you board your flight from Genève Aéroport, you use infrastructure, equipment and services that require ongoing investments and operating costs. These costs are covered by the passenger charge, and from commercial income.
The passenger charge is shown in the "taxes" box of the air ticket and, for Genève Aéroport, is 23.75 CHF, applicable to departures only. It includes the costs of security screening (screening of passengers and hand baggage on boarding and screening of all hold baggage), which account for about 50% of the fee. The other half goes to fund the arrivals and departures halls, waiting and boarding lounges and, more generally, all the facilities directly used by passengers, and also assistance to those with limited mobility.
Any other amounts included in the "taxes" that may be shown on your ticket or invoice do not relate to Genève Aéroport, where the passenger charge is considerably lower than corresponding charges at other airports in Switzerland.