A logarithm, often written as log, is a mathematical function that helps us understand how many times we need to multiply a base number to get another number. For example, in the expression log_10(100), we are asking, "10 raised to what power equals 100?" The answer is 2, because 10 × 10 = 100. Logarithms are useful in various fields, including science, engineering, and finance, as they simplify complex calculations. There are different types of logarithms, such as common logarithm (base 10) and natural logarithm (base e, where e is approximately 2.718). Logarithms can also help in solving exponential equations and analyzing data that spans several orders of magnitude, making them essential tools in mathematics and statistics.