And God created Black and White
Being a video card back in the early days was pretty easy. The CPU did everything; all the video card had to do was draw an image on the screen. As technology advanced, video card duties increased, freeing up the CPU to focus on other tasks (management types call it "empowerment").
With 2D graphics, you have to keep track of all on screen objects and their placement, which can be several layers deep when running in Windows. The system has to keep track of which windows (and their contents) belong where and what parts are visible on the screen.
With the advent of today's modern 3D accelerators and 3D applications, graphics are becoming more complex than ever before. Today's graphics cards are specifically designed to handle more of the 3D graphics pipeline, relieving the CPU of that burden. The newer graphic technology is aiming to take over even greater portions of the 3D pipeline. In theory, this should leave the system CPU free to concentrate on other tasks, such as taking care of the system needs, and operating programs (more advanced AI, etc.).
Advancements in technology
In a sharp contrast to the graphics cards of today, first generation video adapters were monochrome. They could display in only one color and they could only display text of a specific resolution and point size. This limitation was more the result of financial constraints than technological.
The technology to create low-resolution color, graphic capable adaptors did exist early on in the life of the PC, and even rudimentary 3D acceleration was possible, but everything came at a price - a high price that executives knew the general public was not willing to pay. Monochrome did its job, which was primarily as a text display, and it was done cheaply. Monochrome displays kept the personal computer down to an affordable level for the average consumer.
Of course, technology has improved over time and prices have dropped. Display adapters have improved along with the rest of the PC. New technology not only increased the display resolution and refresh rate, but also the amount of characters that could be viewed on screen. Color palettes were inevitably increased. 3D capabilities soon followed.
All video cards use the same basic equipment, but some contain slightly different feature sets or may need special system support. Let's first take a look at the basic components of a video adapter and see what they do.