Two-digit numbers are numbers that range from 10 to 99. They consist of two digits, where the first digit represents the tens place and the second digit represents the units place. For example, in the number 34, the 3 is in the tens place, indicating three groups of ten, while the 4 is in the units place, indicating four individual units. These numbers are used in everyday life, such as in ages, prices, and scores. Understanding two-digit numbers is essential for basic arithmetic and helps in learning more complex mathematical concepts. They form the foundation for understanding larger numbers as well.