The play explores the theme of colonialism through the characters of Prospero and Caliban. Prospero is the rightful Duke of Milan, but he has been exiled to the island by his brother Antonio. Prospero uses his magical powers to control the island and its inhabitants, and he sees himself as the master of the island. Caliban is the son of Sycorax, the witch who was the previous ruler of the island. Caliban is a powerful sorcerer himself, but he is also a slave to Prospero. Prospero uses Caliban to do his bidding, and he often treats him cruelly.
The play also explores the theme of resistance to colonialism. Caliban eventually rebels against Prospero, and he is joined by the other natives of the island. The play ends with Prospero agreeing to give up his power and return to Milan. This can be seen as a symbolic victory for the colonized people, and it suggests that colonialism is not inevitable.