@simrin-- @turkay1 is right, but nominal GDP doesn't always have to be higher than real GDP. If there is deflation in the country (decrease in prices) instead of inflation (increase in prices), nominal GDP might come out less than real GDP for that year. Either way, it doesn't help when comparing between different years where there are price differences.
But you can still make a comparison with nominal GDP if you use the GDP deflator. This is a very simple formula that allows you to compare the price of one good in two separate years. All you need to do is divide nominal GDP by real GDP and then multiply by a hundred. It will give you the ratio of the current price to its base year price.