The shadow mask is a metal screen filled with holes through which the three electron beams pass that focus to a single point on the tube's phosphor surface. Common dot pitch sizes are .25, .26, .27, .28 and .31. The smaller the dot pitch, the sharper the displayed image. This is the type of video card that is in the system. The video card is used to send data to the monitor.
All video cards contain memory that is used to process and store video data.
Video cards are used to display text, 2D and 3D graphics. Cards that use more advanced features often require more memory. AGP refers to the type of bus the card uses. AGP, PCI and ISA are all different types of card buses. AGP is specifically designed for use with video.