Ask
The ask is the price at which the market is offering to sell a currency pair to you.
Topic: Execution
Bid
The bid is the price at which the market is prepared to buy a currency pair from you.
Limit Order
A limit order requests execution at a specified price or better.
Market Order
A market order seeks immediate execution at the best available price.
Slippage
Slippage is the difference between the requested order price and the price at which the order is actually executed.
Stop Order
A stop order becomes active when price reaches a specified trigger level.
Bid, Ask and Spread
Forex quotes have two prices: the bid and the ask. The gap between them is the spread, which is one of the costs of entering and exiting a trade.