A "two-digit" number is any whole number that consists of two digits, ranging from 10 to 99. The first digit represents the tens place, while the second digit represents the units place. For example, in the number 34, the digit 3 is in the tens place, indicating three tens, and the digit 4 is in the units place, indicating four ones. Two-digit numbers are commonly used in everyday life, such as in ages, prices, and scores. They are an essential part of the number system and help in counting, measuring, and performing basic arithmetic operations.