"Philosophical Investigations" is a posthumously published work by the philosopher Ludwig Wittgenstein, released in 1953. It explores the nature of language, meaning, and understanding, challenging traditional views of how words relate to the world. Wittgenstein emphasizes the importance of ordinary language and the various contexts in which it is used. The book is structured as a series of remarks and reflections, rather than a formal treatise. It introduces concepts such as language games and the idea that meaning is derived from use. This work has significantly influenced contemporary philosophy, particularly in the fields of linguistics and philosophy of language.