Core i3/i5/i7 integrated graphics and graphics cards?

I read the core i3 processor has integrated graphics.

In particular for a laptop corei3 wikipedia tells me the processor must be a Arrandale having Integrated Graphics (I am supposing all i3/5/7 have integrated graphics?).

But I have seen a laptop corei3 with Nvidia 1 GB graphics card advertised.

Does this mean that the system has both integrated graophics and a dedicated graphics card?

If so then how will the processor decide when to use its "integrated graphics" as opposed to the Nvidia card - will the nVidia card simply be set up to override the integrated graphics?

Thanks for any info.
Apologies if I am missing something, such as what is the meaning of "integrated" and "dedicated"... I find this a little confusing...

If you are talking about a PC, then it can have either integrated graphics, or a separate graphics card, or both.

If it has both, how it works is that you'll have ports for either one and you choose what you want to plug your monitor into. Otherwise, if it has one or the other, you'll just have the ports for whichever is available.

For laptops, they will always only have one monitor input. So if you get a laptop that has a special nvidia or amd card, then that card replaces whatever would be standard for the laptop. It works differently in laptops, and basically "integrates" these 3rd party graphic cards into the laptop. You can't remove them or anything like a PC can have done.

The motherboard of a PC determines if you'll have integrated graphics because it is based on the CPU chip set (embedded on the motherboard) not the actual CPU processor.

Except in the case of the i3, where the "video card" indeed is in the CPU, however, it does need a motherboard supporting the CPU to use the display.

The same holds true for the new Sandy Bridge processors, where the is a "video card" in the CPU.

Thanks for all answers. I am thinking primarily of laptops. There is a table on the following wikipedia page suggesting that all i3 laptops would contain the Arrandale version...
http://en.wikipedia.org/wiki/Intel_Core#Core_i3
And on the following page it says "Arrandale already contains the major north bridge components, which are ... integrated graphics..."
http://en.wikipedia.org/wiki/Arran [...] ocessor%29
- Doesn't this mean that the graphics are built onto the chip already on Arrandale i3?
- I wonder how a hybrid system decides when it needs to switch between i3 integrated and nvidia - would it be down to specific graphics commands, temperature or what?

"Arrandale is the successor of the 45 nm Core microarchitecture based Penryn processor that is used in the many mobile Intel Core 2, Celeron and Pentium Dual-Core processors. While Penryn typically used both a north bridge and a south bridge, Arrandale already contains the major north bridge components, which are the memory controller, PCI Express for external graphics, integrated graphics and the DMI connector, making it possible to build more compact systems without a separate northbridge or discrete graphics as Lynnfield. The Arrandale processor package contains two dies, the actual 32 nm processor with the I/O connections and the 45 nm graphics controller with the memory interface."