You may ask yourself, do you really need a video card? Well, the answer to that is no, not really but it gives you several advantages if you do make room in your budget for one (or two if you really want to). The Video card is a must for gamers. It gives you the best 3D performance you can get and frees up a lot of RAM. A video card is still advantageous even if you do not play games. It will take the load off you RAM with dedicated video memory (depending on how much you choose) and it will take the load off your CPU and instead giving the task of video to the GPU (Graphics Processing Unit). This frees up your CPU for other things and allows you to multi task.

So what do you do if you don't need a video card? Your only other option is to look into shared graphics. For this you need a compatible motherboard which has a graphics chip built in. Instead of having video memory, it reserves a chunk of your RAM for graphics processing. This significantly slows down your computer when doing photo editing and playing games but for day to day work it should suffice. Nowadays very few motherboards have shared graphics and the ones which do lack many features which you may want or need such as RAID support. For this reason I recommend that you buy a video card, even if it is a very cheap one. They start from as low as AUD$100 and sometimes less. Try looking at something like the ATI HD4670. This is a very basic model but it is slightly better than shared graphics, although you won't be playing many games with it.

There are two different manufacturers of GPU's. These are Nvidia and ATI (now owned by AMD). They sell their GPU's to other manufacturers who make video cards with a GPU from either Nvidia or ATI.

There are several things which need to be put into consideration if you want to buy a video card. Firstly, what is your budget? If you are looking for a mid-range video card which is under $300 or even $200 then you would be looking at an ATI card. They offer very good value video cards which will give you decent performance for their price. If you are looking for a high end graphics card which can cost you upwards of $700, you should look no further than Nvidia. What brand you choose can be your own preference, depending on the brand you might get a silent card with no fan but a large heatsink or one with a fan. Apart from this there isn't much difference between them all except for maybe the quality (e.g. the fan used to cool the GPU) but all the manufactures will use the same GPU's as other products with similar model numbers (e.g. if you see a Gigabyte 9600GT and a Palit 9600GT, they will both feature the same GPU made by Nvidia). On your computer, depending on the motherboard, you can put two identical video cards on the same board which will essentially double the performance. The high end graphics cards of both Nvidia and ATI can also be bought in a dual GPU version which features two physical GPU's on one video card. This can give you SLI/Crossfire performance in one card for about 2/3 of the price.

A second factor you need to consider when buying a Video card is the RAM. This can change depending on what your needs are. If you just do a bit of browsing and occasional gaming or photo editing then around 256 or 512MB should be enough. For a high-end user, I recommend 1GB of RAM on dual GPU cards or about 512MB of RAM which should be plenty. Something in between such as Nvidia 768MB cards are ideal. Of course, for the low end user, I would recommend just buying a motherboard with integrated graphics and buy extra RAM because with integrated graphics, your computer will use you RAM in space of dedicated video RAM. If you are using a 32 bit operating system, you need to be careful how much video RAM your graphics card has. In Vista and Windows 7, you are limited to 4GB of RAM including the RAM on your video card. This means that if you have 1GB video card and 4GB of RAM, then you will only have access to 3GB of RAM as the rest is for the video card. This is no problem if you have a 64 bit operating system, but otherwise you need to be a bit careful if you are buying something like the Nvidia GTX 295 which has 1792MB of RAM.

The final consideration is what card to buy. Today, In the day of Windows Vista, you should probably just get a DirectX 10.1 card which is Nvidia's 9xxx and GT 2xx series or ATI's 4xxx or new 5xxx series. All these cards are offered in both low end, medium and high end. The Nvidia 8xxx series and ATI's 3xxx series support DirectX10 while the 9xxx series and 4xxx series support DirectX 10.1. This won't be of any concern to anyone but gamers. For Windows 7, DirectX 11 is coming but it will not be a whole new system like DirectX 10 was but rather, an evolutionary step. ATI has already released its latest 5xxx series for this and Nvidia is on its way to releasing the GT 3xx series cards. You should also take into consideration the fact that some video cards occupy two expansion slots in your case, mainly the high end ones. Usually it's no problem as todays motherboards basically have everything you need, eliminating the need for additional expansion cards. Many motherboards have upto 8 USB ports, built in sound cards, ethernet and some even have wireless. Some of the best cards are incredibly long as well so it is best to search the internet to check if your chosen case will actually fit the video card in it.

These are the main things which need consideration when buying a video card. Firstly, whether you need an inbuilt one or a discrete one. Secondly, your price range and thirdly, how much RAM you need.