Dedicated VRAM is VRAM that comes with the card and is used exclusively by the GPU and no-one else, it is based on a different technology than the DDR RAMs the system use.
Dedicating more RAM to the graphics (only integrated graphics works this way) is actually exactly how 'Shared video memory' works, the system diverts its RAM to the integrated graphics usage.
VRAM requirement on games is not a hard number you have to follow for the game to work (it is not like Hard disk space requirement), but a general rule of thumb stating what kind of GPU you should have. EG if the game has minimum requirement of 1GB VRAM, it is recommending that you have a GPU with at least 1GB VRAM, not actually have 1GB RAM dedicated to video processing.