I know that there are different kinds of shares: A Class, B Class, C Class. And often the class of the share is reflected in the ticker symbol. But what do these distinctions mean? Are there other classes of shares out there? And what are the pros/cons of each share class?
In most cases, the other classes of shares are preferred stock (example, JPM-F). Preferred stock usually pays higher dividends and shareholders get preferential treatment in the event that the company goes under. (Preferred shareholders are behind bondholders in line, but ahead of common stock holders)
In other cases, different classes of shares have different voting rights or pricing. Examples include Berkshire Hathaway B shares. In the case of Berkshire Hathaway B shares, the stock has 1/500th of the rights and 1/10,000th of the voting rights of an "A" share.
You need to be cautious about investing in anything other than common stock -- make sure that you understand what you are getting into. This is not to say that other share classes are 'bad' -- just that many preferred stocks are thinly traded and are difficult to buy and sell.
Classes of shares are not necessarily standardized. Some share classes have preference above others in the event of a liquidation. Some share classes represent a different proportion of ownership interest. Any time you see multiple share classes, you need to research what is different for that specific corporation.