What is the key difference between domestic and international tourism?

The correct answer highlights that domestic tourism entails travel within a single country's borders, while international tourism requires crossing national boundaries. This distinction is fundamental because it affects various aspects of travel, including legal regulations, cultural experiences, and economic implications.

In domestic tourism, travelers often experience their own country’s culture, landscapes, and attractions, thereby contributing to the local economy without the complexities of international agreements or customs regulations. They may travel for leisure, business, or other purposes, but all activities occur within the confines of one nation.

On the other hand, international tourism involves multiple countries and typically requires a more complex understanding of visas, customs laws, and cultural differences, as travelers engage with entirely different countries and cultures. This leads to a broader scope of travel experiences but also presents additional challenges and considerations.

The other options do not accurately define the key difference. For instance, the notion that domestic tourism is somehow less popular does not consider the varying dynamics of travel markets, which can differ from one country to another. Additionally, stating that there are no significant differences overlooks the fundamental distinctions in travel scope, regulations, and experiences that clearly separate domestic and international tourism.