Travel means to travel for leisure or for fun. Tourism is the main industry of the country. Which brought revenue to the people of Thailand and foreigners entering Thailand.
Tourism means traveling for recreation or for fun. The main industry is tourism, a type of Thai country. Thai people's income and the foreign nationals visiting the country Thai.
The tour is a trip to recreation or fun. Tourism is a major industry in Thailand which type of income from the people of Thailand and foreign to the inhabitants of the country.