1 converts written data into sound waves. 2  converts the sound waves from a voice into a digital signal. 3  converts letters from the keyboard into digital format. 4  converts digital sound waves into analog sound waves.
Travel agencies make their money in a variety of ways. The products agents sell have built-in fees that result in a profit for the agency. The amount of the fees and the ways in which they are earned and distributed differ by the type of product sold and the suppliers who provide that product to the agency.
In this case the commission is not based on the entire trip but is calculated for each item individually and according to the contract the agency has with each supplier. The hotel may pay the agency 10 percent on every booking, the rental car 5 percent and the flight a flat fee of $35. The commission is present in the rate the agent quotes and is receivable by the agent only after the trip has been paid and completed as planned.