Strictly speaking, the video card or video board is a "graphics controller" or "display adapter." It can be a separate component—an actual video board you plug into a slot on the motherboard—or it can be incorporated in the motherboard's chipset, which controls the functions of the devices on the motherboard, including the CPU, RAM, PCI and AGP slots, and I/O ports (serial, parallel, IDE, SATA, etc.). "Integrated graphics" refers to a graphics controller integrated into the chipset.
Regardless of the way graphics is implemented on your computer, you need to have driver software installed to see anything on your screen. The driver passes instructions from your software to your graphics controller. In Windows, if you don't install the manufacturer's driver, Windows will use its built-in generic VGA driver, so you will have a display image. However, your control over the display will be limited, and the advanced features of your graphics controller will not be available. When you install the specific drivers for your graphics controller, most of its features will now be available to applications, and some of its user-adjustable driver settings will be available under the Advanced button on the Settings tab of the Display Properties dialogue box (this is for Windows). However, in order to have full access to the controller's features, you need to install the control software from the manufacturer in addition to the bare drivers. ATi calls their control software either the Control Panel (for driver releases through 5.11) or Catalyst Control Center (CCC - for versions since 5.1).
CCC requires .NET Framework to be installed, and runs in the background, needlessly using system resources. Early versions were reported to be buggy, but that no longer seems to be a problem. Nonetheless, for most people, having CCC installed and running is needless overkill when they make few if any changes to their driver settings once their controller is installed and configured. Although ATi states that the old Control Panel is not supported in Catalyst versions after 5.11, I continue to use the 5.11 version of Control Panel with more recent versions of the ATi drivers with no problems (currently I'm on Catalyst 7.1, from January 2007). Note that if you have a recent ATi board (X1xxx series or newer) that supports overclocking from within ATi's driver, you need to use CCC instead of the Control Panel if you want to overclock your ATi display adapter (they call it a "graphics accelerator"). I suspect the Control Panel will not work under Vista.
Catalyst 7.2 includes an overhauled version of CCC which offers "significant performance gains," a substantial reduction in start-up time, and improved "overall responsiveness"; "reduced system resource usage"; "new 3D preview which significantly improves the ability for users to understand the benefits of enabling" the various features available in the driver; and "increased stability." Note that subsequent releases fixed many of the problems introduced in this version.
Catalyst 7.4 improves OpenGL performance for X1xxx boards.
Catalyst 7.5: More OpenGL improvements, and DirectX 10 support for ATi's new HD line.
Catalyst 7.6: Assorted fixes.
Catalyst 7.7: Current. New AVIVO features, some performance improvements for the HD boards, and the usual fixes.
ATi releases a new driver set every month. It isn't necessary to upgrade to each new release—while these often fix existing problems, they can introduce new ones. Also, the improvements are usually only for some graphics boards and may not apply to the one you own. Finally, current drivers support ATi boards only as far back as the 9500 series, so if you have an older board you can't use these anyway.
In all cases, be sure to read the release notes before installing any new driver set, especially the "known issues" for your operating system.
ATi seems to no longer have driver sets earlier than Catalyst 6.1 on its Web site, but you can get earlier versions
here. This site does not have a separate download for the Control Panel, but
this other site has recent official driver sets incorporating the Control Panel (selected releases only)—look for those releases that show CP instead of CCC.
If you happen to have the driver CD for an older ATi board, you can probably get the Control Panel from that.
EDIT: ATi generally offers files that combine the drivers and the control application, and also separate files for each (in other words, you can get just the drivers or just the control application). The driver-only files are usually in this format:
7-1_xp_dd_40211.exewhere 7-1 is the the release version and xp_dd_ indicates the display drivers for WinXP. The stand-alone Control Panel file is 5-11_xp-2k_cp_27345.exe — note the _cp_ which indicates Control Panel (the stand-alone Catalyst Control Center file has _ccc_ in that position).
nVidia has similar unified-driver packages for its products, with a control-panel app which appears to be called
nView. The same cautions remain in effect: Read the release notes before installing any new driver set. nVidia's release notes are much more slick than are ATi's (nVidia has always been much stronger at marketing), but I was amused to see that the list of problems, fixes, and limitations runs to 42 pages for the current release (162.18, 26 July), compared to ATi's single HTML page. Some of this is due to formatting, but still. . . .
So, no, you do not
need the manufacturer's control application, but having it installed and configuring your display adapter properly will greatly improve your computer's graphics performance. You can find out pretty much anything you need to know about configuring your display adapter
here. Just choose Ati Catalyst or nVidia Forceware from the list Quick Links, as appropriate.