Socrates (Greek: Σωκράτης c. 469 BC–399 BC) was a Classical Greek philosopher. Credited as one of the founders of Western philosophy, in reality he is an enigmatic figure known only through other people's accounts. It is Plato's dialogues that have largely created today's impression of him. 
This Socrates is renowned for his contribution to the field of ethics, and is this Platonic Socrates who also lends his name to the concepts of Socratic irony and the Socratic method, or elenchus. The latter remains a commonly used tool in a wide range of discussions, and is a type of pedagogy in which a series of questions are asked not only to draw individual answers, but to encourage fundamental insight into the issue at hand. It is Plato's Socrates that also made important and lasting contributions to the fields of epistemology and logic, and the influence of his ideas and approach remains strong in providing a foundation for much western philosophy which followed.
As one recent commentator has put it, Plato, the idealist, offers "an idol, a master figure, for philosophy. A Saint, a prophet of the 'Sun-Good', a teacher condemned for his teachings as an heretic."  yet the 'real' Socrates, like many of the other Ancient philosophers, remains at best enigmatic and at worst unknown.