The reality is that investing in the stock market carries risk, but when approached in a disciplined manner, it is one of the most efficient ways to build up one's net worth. While the value of one's home typically accounts for most of the net worth of the average individual, most of the affluent and very rich generally have the majority of their wealth invested in stocks. In order to understand the mechanics of the stock market, let's begin by delving into the definition of a stock and its different types.