This is the mid-market rate and is the rate you normally see on the news.
It is called the “mid-rate” because it is always half-way between latest inter-bank BUY and SELL rates for the currency pair.
We compare the latest rates Banks and FX currency converters are offering to this mid-rate and show the percentage
margin you are being charged. It's much easier to compare the vendor rates and see how much it is really costing you when the vendor profit is expressed as a percentage.