A travel agency is a private retailer or public service that provides travel and tourism related services to the public on behalf of suppliers such as activities, airlines, car rentals, cruise lines, hotels, railways, travel insurance, and package tours.
A travel agent is a private retailer that provides travel related services to the public on behalf of suppliers such as hotels, flights, car hire or package holidays (tour operators). A travel agency's main function is to act as an agent selling travel products and services on behalf of a supplier.
Business tourism or business travel is a more limited and focused subset of regular tourism. During business tourism (traveling), individuals are still working and being paid, but are doing so away from both their workplace and home. Some definitions of tourism tend to exclude business travel.