The document discusses the triangle of reference and the relationship between sense and reference in language. [1] It explains that the triangle of reference describes how words suggest ideas in the mind that relate to real-world objects. [2] It then discusses the difference between sense, which deals with relationships within language, and reference, which deals with relationships between language and the world. [3] It provides examples of how expressions can have variable or constant reference and how the same sense can belong to expressions in different languages.