4.19 Bid-ask Spread:
It is common for any currency pair to be quoted with both a bid and an ask price. The former, which is always lower than the ask price is the price at which a broker is ready and willing to buy, which is the price at which the trader should sell.
The ask price, on the other hand, is the price at which the broker is ready and willing to sell, meaning the trader should jump at that price and buy.
Example: EUR / USD 1.1655 / 58
Bid price is 1.1655
Ask price is 1.1658
4.20 Pip:
The minimum incremental move that is possible by a currency pair is known as a pip.
Example:
EUR / USD 1.1655 moves to 1.1660, means the move is equivalent to 5 pips.
USD / JPY moves from 112.05 to 113.05 would be equivalent to 100 pips