Martin Heidegger was a German philosopher known for his influential work in existentialism and phenomenology. Born in 1889, he is best known for his book Being and Time, published in 1927, where he explores the nature of existence and the concept of "being." Heidegger's ideas emphasize the importance of individual experience and the relationship between humans and the world around them. Heidegger's philosophy has had a significant impact on various fields, including literature, psychology, and theology. His thoughts on authenticity and being-toward-death encourage individuals to confront their existence and make meaningful choices. Despite his controversial political affiliations during the 1930s, his work continues to be studied and debated in contemporary philosophy.