Samuel Langhorne Clemens, better known by his pen name Mark Twain, was an American writer, humorist, and lecturer. He is best known for his novels "The Adventures of Tom Sawyer" and "Adventures of Huckleberry Finn," which are considered classics of American literature. Twain's writing style is characterized by humor, satire, and social commentary, and he is often regarded as one of the greatest American writers. Twain's works often explore themes of freedom, individualism, and the complexities of human nature. His writing continues to be widely read and studied around the world.