The IBM Monochrome Display Adapter (MDA) is a piece of equipment that was used a long time ago in computers. It is what made it possible to see things on a computer screen, but only in black and white, not color.
Think of it like a very basic coloring book – instead of having lots of different colors to use, you only have one color to use, which is black. The MDA could put little black dots on a computer screen in different patterns, which made it possible to show letters, numbers, and simple shapes.
It wasn't really that advanced compared to computer monitors today, but it was still pretty cool at the time because it was something new and innovative. It paved the way for new technologies that made it possible to see things in color on computer screens instead of just black and white.