When you are looking at travel and tourism you are looking at the economic relationship within countries or regions where people will visit and boost the economy.
When you are looking at tourism you are looking at the act of visiting an area that has some value in spending money in that area. In turn the area that it visited gets financial gain from having to support an info structure to support an extra population outside of the citizens that pay taxes within the area.
When you look at travel you are looking at those who visit a particular region and the companies that provide the means of getting to and staying at a particular location. The financial benefit to this is that the customer will pay to travel to and stay at a location.
It is important to note that tourism and travel is a symbiotic relationship. For example travelers will use the travel industry to fly to a location in Mexico for vacation and will stay at a resort. The traveler will utilize the tourism industry when the resort they are on is a secure location, has running water is an isolated location and this is rewarded to the location they are visiting as they pay resort fees and spend money in the local area to support the info structure (roads, police etc.) that the city had to spend to ensure the tourist will visit the location.