Interactive Market Course.
Bid is the price at which your trade starts if you decide to open a Sell position. This quote is in the left column.
Ask is the price at which your Buy position will start. This price is in the right-side column.
In the bank exchange office, you encounter the same thing: you are offered to sell currency at one price and buy it at another.
Thus, your trade will start with a small minus until the chart passes the difference between the Bid and the Ask price, which is called the spread. The smaller it is, the more beneficial it is for the trader.