A logarithm base 10, often written as log10, is a mathematical function that helps us determine the power to which the number 10 must be raised to obtain a specific value. For example, if we want to find log10(100), we are looking for the exponent that makes 10 equal to 100, which is 2, since 10^2 = 100. Logarithms are useful in various fields, including science and engineering, because they can simplify complex calculations, especially when dealing with large numbers. They also help in understanding exponential growth, such as in population studies or finance, where values can increase rapidly over time.