NVIDIA CUDA: What is the developer driver?

To develop NVIDIA CUDA programs, the tools needed are:

1. Developer drivers
2. CUDA Toolkit
3. GPU Computing SDK

What is this developer driver? Installing it silently overrides any NVIDIA graphics driver that is already installed. So, how i开发者_StackOverflows the developer driver different from the usual NVIDIA graphics driver? What extra components or functionality does it contain?

The developer driver is available in both 32-bit and 64-bit flavours. If I am developing 32-bit Visual C++/CUDA projects on 64-bit Windows 7, which flavour of the developer driver do I choose? Why?

From the developer download page:

Note: The developer driver packages below provide baseline support for the widest number of NVIDIA products in the smallest number of installers. More recent production driver packages for developers and end users may be available at www.nvidia.com/drivers.

The developer driver is released with the Toolkit and is intended to have wide support for all CUDA capable devices. On the other hand the drivers on the main driver page are released as appropriate; the main drivers have full support for CUDA, but each one may support a subset of devices.

Incidentally, when you install a NVIDIA driver it tells you what version is currently installed and what version you're installing (unless you choose a silent install!).