A floating-point number is a way to represent real numbers in computing that can accommodate a wide range of values. It consists of three parts: a sign (indicating positive or negative), a base (usually 2 for binary systems), and an exponent that scales the number. This format allows for the representation of very large or very small numbers, making it essential for scientific calculations and graphics. In programming, floating-point numbers are often used in languages like Python, Java, and C++. They can represent fractions and decimals, but they may introduce rounding errors due to their finite precision. Understanding floating-point representation is crucial for developers to avoid inaccuracies in calculations.