Portuguese and Brazilians speak the same language. Which of these peoples was formed as a result of migration?

During the period of great geographical discoveries, the Kingdom of Portugal possessed a powerful fleet and seized vast territories of new lands, turning them into their colonies. In South America, the Portuguese invaded Brazil after learning of the discovery of a new continent. These vast and very rich lands belonged to them for several centuries, and many Portuguese emigrated and stayed there. They also brought with them slaves from Africa who worked on the plantations.