-As mentioned before the Video Card is much like a motherboard. It incorporates its own bus, processor, RAMDAC , and memory. Now we need to know how this little guy works and what is it components.
-The processor, the Video Board processor has a job of putting those stunning 3D Graphics on your screen. Some of these chips are running 100Mhz and better. Something to consider about the processor is it's data width. Most cards should have a data width of 64-bit. Anything less may cause slower performance. Look at the chipset of the Video Card and make sure it meets specs. If shopping for Video Cards look for a 3dFX chipset and as many options for the card as possible. This processor offers many features for 3D games and smooth graphics 2D and 3D.
-The Bus, if your motherboard supports it go with a AGP Bus. The AGP (Accelerated Graphics Port) allows for faster data transfer rates and take a heap off of the CPU. If AGP is out of the question go with the PCI card instead. Both offer great performance but the AGP is suited as its own BUS strictly for graphics. This is a newer feature employed by Intel and may not be on your motherboard.
-The memory, this is a big consideration. How much is enough and what types? Ponder this while shopping. Its up to the memory on your Video Board how many colors you can broadcast over the ole monitor. The best way to go is buy a card with as much memory as you can afford. For regular office use, you shouldn't need more than 4MB for the most part. If running high end games you should consider more memory such as 8mb or better. Another thing about memory is memory types. There are about 7 different types I know of that have been and still are in use. Which ones are better really depends on what you want and what the card is going to be used for. Keep a eye out for (SGRAM) or (RDRAM). Both of these are fairly quick especially (RDRAM) which can cruise at 500Mhz. Now we just need a processor compilation for that speed demon.
-The RAMDAC, this determines how frequently the monitor is refreshed. The faster the RAMDAC the better things look on the screen. Some of the cheaper Video cards wont have a separate RAMDAC on the board. Instead it will be built in to the Video Card processor. The higher the RAMDAC the better. Most of this will come into the size of your monitor. If you are wanting a big display by a card with good memory and a good RAMDAC.
-Software, without software to run along with your board you may have problems. This comes down to drivers for the most part. Make sure you get with a manufacturer that is notable. Don't buy junk boards and expect much out of them or the software. I have much experience in this department. When you buy you new hardware make sure and update the drive software for it. Sometimes it out of date after you purchase the card. Updates are usually free and will enhance future compatibility later.