**Simple Definition:**

Integration is a mathematical process that determines the total accumulation of a quantity by finding the area under a curve [a line that represents how the quantity changes over time or space]. It involves adding up infinitely many small pieces to obtain the total sum.

For example, if we want to find the total distance traveled by a car in a given time interval, we can use integration. By plotting the car’s velocity on a graph, the area under the curve represents the total distance traveled.

Very Simple Definition:

Integration is a way to find the total amount by adding up lots of small parts. We use it to figure out how much something changes over time or space.

For example, if we want to know how much water flows through a pipe, we can use integration. By adding up tiny amounts of water over time, we can find the total amount that has passed through the pipe.