Market price is the price at which an instrument can be bought or sold right now. It reflects the level buyers and sellers currently agree on for a stock, forex pair, commodity, index, futures contract, option, or CFD.
The price updates continuously as new orders reach the market. It moves on supply and demand, news, economic data, earnings, interest rates, liquidity, and sentiment.
Market price is a single reference figure, usually the last traded price, but a live market actually quotes two prices: a bid where you can sell and an ask where you can buy. The price you fill at comes from one of those two sides, so it can sit slightly away from the market price you saw.
EUR/USD is trading at 1.0850.
This is the current market price of the pair.
If more buyers step in, the market price can rise above 1.0850. If sellers take over, it can fall below 1.0850. When you place a market order, you fill at the best price available at that moment, which may differ from the 1.0850 you saw.