in lay mans terms £1 =$2 and a loaf of bread cost $2 . if the exchange rate becomes £1=$3 the price of the loaf of bread has to go up too. it means your currency worth decreased against the world bank.this article might help. https://content.imamu.edu.sa/Scholars/it/net/fischer141.pdf
page 5 but since you are planing on a career in accounting you might want to read the whole thing.and my explanation is quite rough but i hope you get the idea