The S corp has the taxable incomes passing through to the shareholders and it's taxed only once on their personal estimate.

C Corporations pay taxes on the profits it makes, and when the profits are assign to the shareholders, they have to declare from it personal tax returns.

If you decide to change from a C to an S, you have to know that S Corp has limited shareholders, so there's something to reconsider.

You need to keep in mind that you can't change permanently from a C to an S, and that you'll face some restrictions if you decide to do it.

Check this site out, you'll find useful legal info about this topic.

Best of luck