As I had went through earlier, the Stock Quote primarily shows the price of a stock on its exchange market and updated real-time (usually) during a trading session. But what or how is the stock price determined?
Economics 101 explains that price is determined by the Law of Demand & Supply. The equilibrium market price of a stock is the price at which the seller is willing to let go and buyer willing to acquire.
The infographics further illustrates how a stock price is determined against the perceived value by both investors and traders.
Theory of Constraints 