Ludwig Wittgenstein was an Austrian philosopher, born in 1889, known for his work in logic, language, and the philosophy of mind. He is best known for two major works: the Tractatus Logico-Philosophicus, which explores the relationship between language and reality, and Philosophical Investigations, which critiques his earlier ideas and emphasizes the use of language in everyday life. Wittgenstein's philosophy has had a significant impact on various fields, including linguistics, cognitive science, and artificial intelligence. His ideas challenge traditional views of meaning and understanding, suggesting that language is a tool shaped by its practical use in different contexts.