Vector calculus is a branch of mathematics that involves understanding how vectors (arrows) are affected by different operations like adding, multiplying, and dividing them. To understand vector calculus, you need to think of things like lines, circles, and other shapes in three-dimensional (3D) space. To work with these shapes and their properties, you need to be able to calculate things like the length of a line, the area of a circle, or the angle between two lines. Vector calculus helps you do this by everyday operations and techniques, like adding and subtracting vectors, taking their dot product and cross product, and integrating and differentiating them. With these techniques, you can figure out things like how fast something is moving or how quickly something is changing.