The term last price is used to describe the most recently reported trading price for an equity or a futures contract. While there may be many last prices during a trading day, a stock's closing price is always a last price too.
When an individual wants to invest in an equity or futures contract, there are several prices they may be quoted. This includes the security's bid and ask price, which is oftentimes quoted in pairs as the bid / ask prices. The difference between these two values is referred to as the bid / ask spread. These two values represent the current price at which an investor is willing to sell a security (ask) and the current price at which an investor is willing to buy a security (bid).
As new trades are completed, a third value is introduced: the last price. As the name implies, this represents the last price at which a trade occurred. The last price is typically shown on charts, and updated as new trades occur.