ASK: the price of the base currency at which the dealer is willing to sell in exchange for the quote currency. In simple words, the ask is the price at which you will buy.
SPREAD: the difference between the ask and the bid prices. In other words, it is the difference between the market maker's "selling" price (to its clients) and the price the market maker "buys" it from its clients.
By the way, the BID is always lower than the ASK. The reason for this mystery is that the SPREAD (the difference between the bid and the ask prices) is how FOREX brokers get paid for their services without charging you with commissions or special fees.