In OpenCV, the cv2.copyMakeBorder() function is used to add a border to an image. It creates a new image with a border around the original image, where the size, type, and color of the border can be specified. The function requires several parameters:

1. src: The image to be modified.
2. top, bottom, left, right: The number of pixels to add in each respective direction.
3. borderType: The type of the border to be added.
4. value: The color of the border, specified as a tuple of Red, Green, Blue, and optionally Alpha values.