What is Real versus Nominal value?

Nominal money is the amount of money you have. Real money is the value of that money.

If Alice had $50 in her purse in January 1970 and Bob had $50 in his wallet in January 2020, they both have the same nominal amount of money. Due to inflation, however, Alice's $50 is worth much more than Bob's $50. If you wanted to do a meaningful comparison of how much wealth each had, you'd need to convert nominal money into real money. One way to do that is to look up historical inflation (or use an inflation calculator). That shows that Alice's nominal $50 was worth a real $548.87. That is, Alice could get almost 11 times more goods and services for her money than Bob could get for his.

From a personal finance perspective, if you're putting money in a savings account that earns 0.5% interest while inflation is averaging 2%, the amount of money you have in nominal terms is increasing at 0.5% per year. But the amount of real money you have is decreasing at a rate of 1.5% per year since you're not making enough to keep up with inflation.

The article you linked to is called

Real versus nominal value (economics)

You changed the title in your question to "Real versus nominal money (economics)"

That changed the meaning completely. The idea of the article and the more general article it mentions at the top is that everything has two values: the real value and the nominal value.

In economics the difference between the real value and the nominal value is how you factor in inflation. When a grand-parent and grand-child compare the minimum pay when they started work, they need to have a way of comparing the rate by noting items such as the price of milk, the price of gas, or the price of a movie. When they do that they are now using the real value of the minimum wage at the times they are comparing.

In 1950 a $1 bill could buy a decent amount of groceries: eggs, milk, bread, with change to spare. In 2020 it won't even buy you a dozen eggs. It's real value has declined. But, it's still worth exactly $1. It's nominal value has not changed.