Jamieson, Fausset and Brown on Genesis 41:8

8. he called for all the magicians of Egypt--It is not possible to define the exact distinction between "magicians" and "wise men"; but they formed different branches of a numerous body, who laid claim to supernatural skill in occult arts and sciences, in revealing mysteries, explaining portents, and, above all, interpreting dreams. Long practice had rendered them expert in devising a plausible way of getting out of every difficulty and framing an answer suitable to the occasion. But the dreams of Pharaoh baffled their united skill. Unlike their Assyrian brethren (Da 2:4), they did not pretend to know the meaning of the symbols contained in them, and the providence of God had determined that they should all be nonplussed in the exercise of their boasted powers, in order that the inspired wisdom of Joseph might appear the more remarkable.