Tourism, the largest industry in the worldTourism is a typical fashion activity in which the public participates widely and which has grown in importance over the human history. Countless articles call tourism “the biggest industry in the world”; policy makers, analysts and academics often talk about the size of tourism relative to that of other industries (Smith 2004: 26). This series of misleading statements, along with media reports (out of context), cause the idea of ​​tourism to be a single large industry to be ingrained in many people's minds. However, in this essay I will demonstrate that this is a simplistic and misleading idea, which should be replaced by the plural term “tourism industries”. Furthermore, tourism is not the largest industry in the world, but the largest service sector. Is tourism an industry and if not, what is it and how can it be defined? To answer these questions, we first need to find the definition of industry. An industry is a group of companies producing products and/or services that are close substitutes for each other (……). To be considered an industry, it must meet three factors: individual businesses, the revenues of those businesses, and a common product. Now let's see what tourism is. However, there is no single definition, that is, agreement on what tourism should be. There are several reasons for this: tourism includes a number of diverse sectors (e.g. transport, accommodation, attractions, other services); tourism includes a number of academic subjects – some argue that as a subject tourism is conceptually weak; it is difficult to establish strict boundaries around tourism, both as a business and as a field of academic study; weak data sources, making cross-country comparisons difficult.