A hypercube is a geometric shape that extends the concept of a square and a cube into higher dimensions. A square is a 2-dimensional hypercube, while a cube is a 3-dimensional hypercube. In general, an n-dimensional hypercube is called an n-cube. For example, a 4-dimensional hypercube is known as a tesseract. Hypercubes can be visualized by connecting the vertices of lower-dimensional cubes. For instance, a tesseract can be represented as a cube within a cube, with corresponding vertices connected. Hypercubes are important in various fields, including mathematics, computer science, and physics, as they help in understanding complex structures and multidimensional data.