Do intel graphics run alongside a video card?

I am just wondering how the integrated graphics on an i7 work with a video card. I see that they are both recognised as graphical devices but do they run together or do they come into play during the use of different applications such as the i7 for browsing and the video card for gaming? I would just like to know how it works, thanks!

No it does not as soon as you put a graphics card in the pci slot that takes over the graphics side of things :)

Not true. All you need are 2 connectors. 1 for your Motherboard to your monitor, the next for your graphics card to connect to your monitor. 

I Litecoin mine with 2 GPUs and I'm able to use my PC's integrated graphics. You can also make something called a "dummy plug" to keep your GPU active when you're not using it.

Now the situation above is only if you need to use both at the same time but only have 1 monitor.

If you have a Virtu MVP (or other Virtu software) enabled Motherboard then you may be able to run both integrated and dedicated graphics alongside during gaming however it's very hit and miss and most people will tell you that even with their most updated drivers, finding stable FPS during gaming is gambling at best.