Tourism indicators by country from The World Bank

Definitions

International tourism, number of arrivals - International inbound tourists (overnight visitors) are the number of tourists who travel to a country other than that in which they usually reside, and outside their usual environment, for a period not exceeding 12 months
International tourism, number of departures - International outbound tourists are the number of departures that people make from their country of usual residence to any other country for any purpose other than an activity remunerated in the country visited. 
International tourism, receipts (current US$) - International tourism receipts are expenditures by international inbound visitors, including payments to national carriers for international transport. These receipts include any other prepayment made for goods or services received in the destination country.
International tourism, receipts for passenger transport items (current US$) - International tourism receipts for passenger transport items are expenditures by international inbound visitors for all services provided in the international transportation by resident carriers. 
International tourism, receipts for travel items (current US$) - International tourism receipts for travel items are expenditures by international inbound visitors in the reporting economy. 
International tourism, expenditures (current US$) - International tourism expenditures are expenditures of international outbound visitors in other countries, including payments to foreign carriers for international transport.
International tourism, expenditures for passenger transport items (current US$) - International tourism expenditures for passenger transport items are expenditures of international outbound visitors in other countries for all services provided during international transportation by nonresident carriers. 
International tourism, expenditures for travel items (current US$) - International tourism expenditures are expenditures of international outbound visitors in other countries.