the way I see it its like the difference between a physicist and an engineer
The wizard is like a physicist, he/she has a near perfect understanding of the theory behind how the world works, but can put less of it into practice at a given time (fewer spells per day, more spells overall). In addition to this, wizards spend long amounts of time in their Ivory Tower (possibly literal) and don't tend to have a good deal of practical knowledge about how the world works.(low charisma high int)
The engineer is the sorceror. He/she tends to have a decent general knowledge of the theory behind the work, but focuses more on the practical application of it (less spells but more uses per day and more flexible use of known spells). The sorcerour does not need to focus as hard on the theoy, though a working knowledge of it is still important, as the wizard and thus is able to spend more time out in the world learning practical things and learning to work with people (high Charisma)
*disclaimer, no offence intended to physicists, out there, I am an engineer. I tried to be unbiased but probably did not succeed.