Linear interpolation is a method used to estimate unknown values that fall within two known values on a straight line. It assumes that the change between these values is constant, allowing for a simple calculation. For example, if you know the values at points A and B, you can find the value at a point C that lies between them by using a straightforward formula. This technique is commonly used in various fields, including mathematics, engineering, and computer graphics. It helps in creating smooth transitions between data points, making it easier to predict values in scenarios like data analysis or image rendering.