The sine function, often abbreviated as sin, is a fundamental mathematical function in trigonometry. It relates the angle of a right triangle to the ratio of the length of the opposite side to the hypotenuse. For an angle θ, the sine is defined as sin(θ) = opposite/hypotenuse. This function is periodic, meaning it repeats its values in regular intervals, specifically every 360 degrees or 2π radians. Sine is widely used in various fields, including physics, engineering, and computer graphics. It helps model wave patterns, oscillations, and circular motion. The graph of the sine function is a smooth wave that oscillates between -1 and 1, illustrating its periodic nature.