The integral, or antiderivative, is the basis for integral calculus. It tells you the area under a curve, with the base of the area being the x-axis. Its symbol is what shows up when you press alt+b on the keyboard. It can also be written as d^-1y/dx^-1. The process of finding an integral is known as integration or antidifferentiation.
The antiderivative of sin x from x=0 to x=2<pi> is 2.
The antiderivative of sin x without boundaries is -cos x. (?sin x dx = -cos x)