Hindu-Arabic numerals are the ten digits used in most of the world today: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. They originated in ancient India around the 6th century and were later transmitted to the Islamic world, where they were adapted and spread to Europe by the 10th century. These numerals are significant because they introduced the concept of zero and a positional decimal system, which allows for efficient calculation and representation of numbers. This system replaced the more cumbersome Roman numerals, making mathematics and commerce easier and more accessible.