Epistemology is derived from the Greek word episteme which means knowledge and logos which stands for theory.

It studies the philosophical nature of knowledge including its definition, the various types of knowledge, the matter of certainty, and the limits to knowledge. It explores how individuals come to know something and what it is that they actually know.

The word sophists comes from the Greek sophistes, meaning an expert or man with wisdom or even master craftsman.

Sophists were regarded as travelling teachers who charge to give instruction.