A logarithm 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 base 10 of 100, we are asking, "How many times do we multiply 10 to get 100?" The answer is 2, because 10 × 10 equals 100. Logarithms are useful in various fields, including science and finance, because they can simplify complex calculations. They also help in dealing with exponential growth, such as population growth or compound interest, by transforming multiplicative processes into additive ones, making them easier to analyze.