From the perspective of movement of people there are still many possible answers to that basic question. Lets dive in!
When people travel for business or work, the term that better describes the travel is commuting. The estimate of people working is at 3.3 billion and majority of them commute to work. According to data from Eurostat for 2019, people who commuted to work in European Union and associated regions (EFTA, United Kingdom and Turkey) are 245 million, and that is roughly 92% of the employed personnel (267 million people). For the same year of statistics (2019), the United States Census Bureau estimates that 148 million workers in the United Staes of America commuted to their workplace and another 9 million people were working from home. In 2023, the data from Statistics Canada showed that 15.9 million Canadians commuted to work, which is about 78% of the employed people. However, for these regions the commute to work is predominatly by a motor vehicle or bike. In other regions of the world, a huge proportion of the workers commutes by foot, wchich cannot be regarded as travel.
When people travel for entertainment, it is more appropriate to call it touristic travel. The number of tourists in 2022, which are traveling internationally was 960 million.