A definite integral is a mathematical concept used to calculate the area under a curve defined by a function over a specific interval. It helps us find the total accumulation of quantities, such as distance, area, or volume, between two points on the x-axis. The result of a definite integral is a number that represents this accumulated value. To compute a definite integral, we often use the Fundamental Theorem of Calculus, which connects differentiation and integration. By evaluating the integral from one limit to another, we can determine how much the function changes over that interval. This is particularly useful in fields like physics and engineering, where understanding changes over time or space is essential.