A regular corporation is also known as a C-Corporation. The difference between a C-Corporation and an S-Corporation fall mainly into three categories; the first is taxation.
A C-Corporation is subject to double taxation. That means that the entity or the corporation itself is subject to tax and then the economic benefits that flow through from that C-Corporation to the individuals are taxed at the individual level.
With an S-Corporation there is no taxes on the S-Corporation itself, instead, all of the elements of the economics and so forth flow through or are passed through the corporation to the individual owners and those results show on their individual 1040’s. The results show by percentage of ownership so if you have a 100% owner then they report 100% of the results, a 20% owner reports 20% of the results.
The second way that the two are different is that a C-Corporation can have multiple classes of shares. They can have preferred stock, they can have common stock, they can have more than one kind of common stock, more than one kind of preferred but an S-Corporation can only have one type of share, one type of ownership and all of the shareholders must be treated equally.
The final difference between the two types of corporations is that an S-Corporation can, for the most part, only be owned by individuals while a C-Corporation can be owned by other companies, other partnerships, basically any sort of entity or person can own a C-Corporation and that’s why all publicly traded corporations are, in fact, C-Corporations.