A bid price is the highest price that a buyer is willing to pay for a good and ASK Price
is the price at which the market is ready to sell a good.
Just re-call how you negotiated on the price
Before you purchased the TV to your home.
And on the other side the seller of the TV re-negotiated on your price.
This is what typically happens in the currency market too.
Assume you want to buy 10000 euros for a vacation to Europe.
The buyer of your dollar or seller of Euros would offer you 1.130 per dollar.
On your return if you want to exchange your left-out euros to dollar again, the buyer of euros would offer you the low price 1.120
The difference between the buy and sell price is called spread, ideally that is the profit of broker or currency exchange
Forex prices are always quoted using five numbers; so, for this example, let’s say we had a EUR/USD bid price of 1.12000 and ask of 1.12050.
Thus, the spread would be equal to 0.05, or $0.00050