Zettel is a collection of notes by Ludwig Wittgenstein (1889–1951), written from 1929 to 1948, personally selected by him as most significant to his philosophy. Perhaps the collection was intended for further publication or use in other works. The notes touch on all the main topics that occupied Wittgenstein all these years and until his death. The formulation of key questions and possible answers - what is language, a sentence, the meaning of a word, language games, everyday life, a machine, pain, color, learning to use words and much more - are given in this collection of notes as clearly as possible for Wittgenstein, in a multifaceted way and not without literary grace. Zettel is an essential source for understanding his philosophy and its potential for philosophical work today. The book's publishing layout is preserved in PDF A4 format.