This document outlines the key elements of a tourism system based on three models: Leiper's model identifies three elements - the generating region, transit region, and destination region. Mill and Morrison's model focuses on the market, travel, destination, and marketing. Gunn's model emphasizes the supply and demand dimensions, identifying tourists as the demand side and facilities, attractions, and land uses as the supply side. It also discusses five basic travel motivations (physiological, cultural, social, spiritual, fantasy) and the three main supply side components: resources, government, and the tourism industry.