A "trilogy" is a set of three related works, often in literature, film, or other forms of art. Each part typically tells a part of a larger story, allowing for deeper character development and complex plots. Popular examples include The Lord of the Rings by J.R.R. Tolkien and the Star Wars original trilogy. Trilogies can also explore different themes or perspectives across the three installments. They often build on each other, with the first part introducing the characters and setting, the second part escalating the conflict, and the third part resolving the story. This structure can create a satisfying narrative arc for audiences.