Complex sentence: In typography, an asterism is a rarely used symbol consisting of three asterisks placed in a triangle: ⁂, and it is used to call attention to a passage or to separate sub-chapters in a book.
Split into simpler sentences: In typography, an asterism is a rarely used symbol consisting of three asterisks placed in a triangle (⁂). People use it to call attention to a passage or to separate sub-chapters in a book.