The most important result of the Treaty of Tordesillas was that the area that we now call Latin America was divided up between Spain and Portugal. Spain was given by far the greater part of this area. However, the treaty did allow Portugal to take control of what is now Brazil.
After Columbus “discovered” the New World, the Spanish and the Portuguese started to argue about who should control any new discoveries. They eventually got the pope to negotiate a compromise between them. The pope at the time, Alexander VI, was Spanish and his decision favored the Spanish more than the Portuguese. The Spanish and the Portuguese then negotiated further and the line dividing the two territories was moved farther west, in favor of the Portuguese. When they came to an agreement, they signed the Treaty of Tordesillas.
The most important result of this treaty was that Central and South America were divided up between Portugal and Spain. Spain got most of the land, but the line was far enough west to give Brazil to Portugal.