This document discusses the growth of tourism as a global phenomenon and some of the factors driving this growth. It addresses how leisure time is increasingly defining people's lives and how they spend their non-work periods. The document also touches on reasons for the increased role of tourism, including changing economies focused more on services and consumer industries. Sustainability concerns related to tourism's expansion are also mentioned. Overall, the document provides background on why tourism has become a major global activity and introduces some of the concepts and forces shaping the tourism industry.