A Pixel Buffer is a temporary storage area in computer memory that holds pixel data for images or graphics. It allows for efficient rendering by storing the color and brightness information of each pixel before it is displayed on the screen. This helps in managing how images are drawn, especially in applications like video games and graphic design. When a program needs to update the display, it can quickly access the Pixel Buffer to retrieve the necessary pixel information. This process minimizes delays and improves performance, ensuring smoother visuals and a better user experience in graphics-intensive applications.