Roman numeral is a kind of digital used in Europe before the introduction of Arabic numerals (actually Indian numbers), and now it is less used. It came into being later than the numbers in Chinese oracle bone inscriptions and later than the Egyptian decimal numbers. However, it marks the progress of an ancient civilization. It's just that there's no number 0.

In July 2015, Rome, Italy, said it would give up using Roman numerals because it was too complex for modern people. Parliament has ordered that street signs and official documents be written in Italian.

Source: @kuttieink