What were Socrates's positions? Why did he defend them?

Socrates was a philosopher who lived in ancient Athens from 470 BCE until his death in 399 BCE. He wrote nothing himself, and his views are mainly known to us through the works of Plato and Xenophon, in which he plays a major role. Socrates also figures in Clouds, a comic play by Aristophanes. As the portraits of Socrates in these three sources vary considerably, one can only legitimately talk about the views of Socratic characters in these sources.
The Socrates of Plato describes himself in the dialogue Theaetetus as a midwife who has no wisdom of his own but rather one who helps others bring forth their own ideas and tests them by means of a method of questioning called elenchus. In this account of Socrates, which is in accordance with Socrates's behavior in many of the early Platonic dialogues, Socrates does not have a fixed set of positions but rather a method of inquiry which relies on the notion that truth can be discovered by close examination of ideas. In Apology, Socrates states that his habit of asking questions is a divine mission, authorized in part by the Delphic oracle.
The Socrates of Xenophon is much more conventionally pious than that of Plato and is far more often (than Plato's Socrates) guided by his daimon, a sort of inner divine voice, to act in a certain matter.
In Aristophanes, Socrates is promoter of an unorthodox religion and a charlatan who obtains money by teaching privileged young men the art of clever speech.