A view frustum is a geometric shape that defines the visible area in a 3D environment, such as in computer graphics or video games. It resembles a truncated pyramid and is created by projecting a camera's field of view into the 3D space. The frustum helps determine which objects are visible on the screen and which can be culled or ignored during rendering, improving performance. The view frustum is defined by six planes: the near and far clipping planes, and the left, right, top, and bottom planes. These planes work together to create a volume that contains all the objects that the camera can see, ensuring that only relevant data is processed for rendering, which is crucial for efficient graphics rendering in applications like virtual reality and 3D modeling.