The document discusses several key concepts in tourism theory and practice. It defines tourism as travel for recreational, leisure or business purposes that involves staying outside one's usual environment for over 24 hours and less than a year. It also provides definitions of tourism from different academic writers that reference the interactions between tourists, suppliers, governments, and communities. The document also briefly discusses the relationship between supply and demand in tourism and the importance of transportation systems like railroads, boats, automobiles, and air travel in facilitating tourism over time.

1. TOURISM THEORY AND PRACTICE