What is the Bid price? What is the Ask price?

What is the Bid price? What is the Ask price?
When you request a quote for a stock, you will receive the bid price and the ask price. The bid price is the best (highest) price you might receive if you sell your stock back to the market. The ask price is the best (lowest) price you might receive if you buy stock from the market.
You are not guaranteed to get these prices because the market fluctuates constantly and prices change quickly. Also, if you buy (or sell) shares of a low-volume stock, you run the risk of affecting the price due to excess demand (or supply).